Did you know there’s a feature in Google Ads that can increase your CTR by up to 20%?
According to Google’s own research, ad extensions can do exactly that.
As its name suggests ad extensions expand your ads with additional information to make them irresistible to searchers. The ad extensions can range from extra links, call buttons, and location information right to the specific pricing info.
However, using ad extensions and knowing when, why, and how to use them are two different stories.
Throwing around every type of ad extensions without a clue can work against you as misusing this Google Ads feature can result in a lower CTR.
So in this Google Ads Ad Extensions Guide, I’ll show you how to use the different types of ad extensions efficiently with your ads with the goal to increase your CTR.
After reading this article, you’ll know:
- The benefits of using ad extensions in your Google Ads campaigns
- The common mistakes advertisers and online store owners make when they are using ad extensions
- The complete list of ad extensions you can use for your ecommerce store and how to use them (with examples)
- How to analyze the performance of your ad extensions
How to 5x your Ad Real Estate (and CTR)
Now that you know what ad extensions are, it’s time to look at the difference between an ad that uses them vs one that doesn’t.
Our first example uses a lot of ad extensions:
After the headlines and descriptions, you can see that the store lists the types of teas it is selling.
They also use an ad extension that allows them to include links to the store’s different products (e.g., Chai teas, Black teas).
And they display a promotion for “Loose Tea Samplers” with a price tag (from $9.00).
Before diving deeper into the different extensions, let’s look at an ad without any extensions.
This ad is from the exact same company.
It has two headlines, a brief description line, and a display URL. But there are no ad extensions to accompany it.
Now go back to the first ad that used multiple extensions. Would you rather click on that ad or the one that used no extensions?
I’d go with example number one. And here’s why.
Let’s say I’m searching to buy loose leaf tea online searching for the ecommerce store with the best variety of tea.
When I look at the second ad, I can see that Adagio is selling loose leaf tea with some promotional offers (e.g., free shipping), has low prices and claims to have a decent variety of tea.
However, all the features and benefits, except for the 10% cashback, are kinda vague, the ad shows nothing specific.
Also, the information the ad provides could not be sufficient to evoke a desire in me to click.
I’m not saying it’s a bad ad, or that the copy is flawed, but I just need more information.
If you look at the ad with the extensions, you’ll see that it includes lots of useful info.
I do not just see “huge range,” but the ad shows me that Adagio sells at least eight types of tea. I can even click on the links for the different categories.
As I’m looking for an online tea shop with a decent variety of tea, I find the use of these extensions great.
Also, I can see that l can even sample each tea type with a price tag and a link to click.
From the store owner’s perspective, as the price is displayed in the ad, I can significantly reduce the number of people who bounce from my site because they have found the price of my products too expensive.
The Secret Powers of Ad Extensions
I hope that the example above has shown you how ad extensions help make your ads more relevant to potential customers and help them stand out from competitors.
Making your ads more relevant is not just good for your business. Google also focuses a lot of its attention on making sure the ads are good. Because without relevant ads, people would stop clicking, and Google would stop making money!
The most crucial thing they did to ensure relevant ads was to put stops in place for advertisers to buy their way to the top of the search results.
They do this through something called quality score. It’s a score between 1 and 10 and it’s Google estimate of how relevant your ad is to a specific search query.
Google multiplies this quality score with your max CPC to calculate in which position of the search results your ad will show up.
The higher your quality score, the less you have to pay to rank in the same position.
They also factor in how effective you’re using ad extensions.
Over the years Google has stayed pretty vague on exactly how this impacts the Ad Rank.
But it tells us that Google thinks ad extensions are important, so it’s essential to learn how to use them effectively!
Ad Extensions Overdose
While you can see that ad extensions have plenty of benefits, the improper use of this Google Ads feature can backfire.
The main goal of using ad extensions is to make your ads more relevant to your searchers, which could eventually increase your CTR.
However, if you are just throwing extensions on your ads not caring about relevancy, then you are hindering the performance of your Google Ads campaign.
It can hurt your CTR, your rankings, and can result in a disappointing ROI and ROAS.
Common mistakes related to the use of ad extension include adding too many as well as adding non-relevant ones, and leaving out extensions that could improve your relevancy.
Let’s see an example of the wrong use of ad extensions.
You can see that there are multiple issues with this ad.
Firstly, it states in the headline that if you call the consultation service for the first time, then your call is free.
But do you see a phone number in the ad?
Instead of the phone number, three sitelinks are listed.
As your goal is to searchers call you for a free consultation, listing the sitelinks are contradictory to your objective.
Take a look at the fixed version:
As you can see, I added a phone number as well as deleted the sitelinks. An overall rating of the consultation service is also displayed to create trust for searchers.
Remember to use ad extensions wisely. Your ultimate goal should be to make your ads more relevant to your searchers.
If you nail that, your CTR will also go up.
Essential ad extensions for ecommerce
Google offers a lot of different ad extensions for advertisers, but they aren’t relevant for ecommerce businesses.
So in what follows, I’ve selected the ones that are most important to improve the CTR of your ads.
Adding these ad extensions won’t cost you anything extra. If you add them, they can show up, and you pay for each click like in the case of ads where you don’t use extensions.
Automated vs. manual ad extensions
Ad extensions can be categorized as manual and automated.
The main difference between the two is that who sets them up.
Manual extensions have to be set up by you, while Google will add automated extensions automatically (they are turned on by default in Google Ads).
Although you are the one setting up manual extensions, Google will determine when to show them. The same is true for automated extensions.
Now let me show you the types for both categories starting with manual extensions.
Sitelink extensions are one of the favorite ad extensions of ecommerce store owners.
Do you know why?
Because you can add extra links to your ad that can direct your searchers to specific pages of your website.
While there’s only a little effort needed from your side, sitelink extensions can add tons of value to your ad.
What do sitelink extensions look like
You are a tea lover, and you want to buy a great infuser for your newly arrived loose leaf tea.
So you head up to Google and hit some keywords in the search bar.
One of the ads that you see is the one in the above image.
While it becomes clear to you that the store sells tea infusers, you discover that you can buy different types of tea from the same service (e.g., herb tea) as well as tea makers.
Therefore, you may check the tea collection of the store. You were also wondering about methods how to make tea faster, so you may also click on the sitelink for tea makers.
Do you see the real power of this extension now?
While my example showed you that sitelinks could be used to showcase other relevant products or services, you can also use this ad extension type to provide more information to the prospect about your store and products as well as to offer free trials and promotions.
How to add sitelink extensions to your ads
To add sitelink extensions to your ads, you need to create the extension first.
In your Google Ads account, click “Ads & extensions” in the menu on the left-hand side, click the plus icon and select sitelink extensions.
The first thing you’ll see on the top left of the page is “Add to.” The default option in Google Ads will add the extension at the account level.
If you don’t want to apply the sitelink extension to each and every ad you have created, then I’ll recommend you to change that setting to either campaign or ad group.
In case you choose to create a new sitelink extension (you also have the option to use existing ones), then you’ll have to write the text for each sitelink and add the final URLs (where the sitelink redirects the prospect) to them.
You also have the option to add two lines of description to each of your sitelinks, but this choice is optional and totally up to you.
The sitelink extensions character limit is 25 characters for the text, and 35 for descriptions and the final URL.
Please note that Google requires you to add a minimum of two sitelinks to your ad.
Also, if your ad will show for desktop users, it will display a maximum of 6 sitelinks, while Google will show up to 8 sitelinks for mobile and tablet users (in the form of a carousel).
When you have finished with writing the copy for the sitelinks, head to the bottom of the page where you’ll find advanced settings.
Inside advanced settings, you can schedule your extension to appear as well as you can set the specific times and hours when your sitelinks should show for searchers.
You also have the option to set mobiles as the preferred device for your extension.
Pro tip: I recommend adding as many sitelinks as you feel is enough for your ad as well as a combination of different extension types per ad group.
This ad extension type allows you to expand your ad with unique offers, promotions, discounts, USPs as well as features and benefits of your products and store.
The goal of callouts is to add relevant text to your ad that will give them one more reason to click your ad.
Callouts are one of the most popular extensions among advertisers as it’s super easy to set up (taking only a few minutes). Also, everyone can use this extension without any restrictions.
Callout extensions are great for saving up space in your ads that you can use to add more useful information.
What do callout extensions look like
The ad in the example above was triggered for the query “buy mobile charger”.
While you can see that the store used sitelinks to showcase different products of its store to the searchers, the callouts above feature the store’s benefits, such as its 24/7 live chat service.
You can clearly see that the callout extension the store used saved up plenty of space in its ad, so it can focus on its Chinese New Year promotion in the ad copy.
How to add callout extensions to your ads
To add callout extensions, you need to navigate to the “Ads & extensions” menu in Google Ads, then create a new callout extension.
Google allows you to add between 2 to 6 callout extensions to your ads. Unlike sitelink extensions, the same number of callouts will show for desktop and mobile/tablet users.
The character limit for each call out is limited to 25 characters for most languages (except Japanese, Korean, and Chinese where the limit is 12 characters).
In advanced settings, you have the same options as with sitelinks (mobile preference, scheduling, and days and hours for the extension’s uptime).
Pro tip: Use callout extensions to highlight the USPs of your products and store.
And because these USPs don’t have dedicated landing pages, it’s better to use them here instead of sitelinks.
Most of the time, including a promotion in your ad copy goes at the expense of the benefits of your store and products due to Google’s character limit.
And you don’t want to lose potential customers because you’ve failed to showcase how awesome your store and products are.
But with promotion extensions, you can highlight your sales, promotions, and discounts for prospects that are searching for the best deals so you don’t miss out on showing searchers the best features of your store and products.
What do promotion extensions look like
Now let’s see an example for this ad extension type.
Under the copy, the ad shows a line with a special sale for Easter as well as a link searchers can use to navigate to the store’s page where they can purchase items with discounts (in the case of my example, the final URL for the promotion extension is the homepage of the store).
It’s important to highlight that the ad uses an occasional promotion (Easter), which you can set in Google Ads (I’ll show you how a bit later in this article).
However, it is not necessary to add an occasion for your promotion. You can have a general one like in the example above.
How to add promotion extensions to your ad
When you are inside the “Ads & extensions” tab and have clicked the “+” icon, you need to select promotion extension from the Google ad extension list.
This page will look a bit different from the earlier extensions.
As mentioned before, you can select the occasion for your promotion (Google supports plenty of events for promotions) that will show with bold before the text of the extension.
If you don’t have an occasion for your discount, select “None” from the list.
You can also choose the type of your promotion with its values (e.g., $10 or 15%) as well as the language and currency used for the discount.
If you have finished with setting that up, you can write the extension’s text as well as add the final URL.
An optional step is to include details about your offer, such as a promo code or a minimum order limit that would trigger your promotion.
Below that option, you can set the start and the end date of your promotion, but it is not a mandatory step.
There’s a new tab, URL options, where you can set up tracking for your extension URL (I’ll talk about performance tracking later in this article).
And finally, you have advanced options that are the same as at other ad extension types.
Pro tip: Adding occasions is an excellent way to appeal to holiday shoppers.
Also, if you have a coupon code, don’t forget to display it in your promotion ad extension.
If Google Shopping and text ads had a baby they would be called price extensions.
While this extension won’t let your ad to show an image for a product in your store, you can still display the price for the product as well as a link.
Price extensions won’t just save you space in the copy, but they will help shoppers on their journey in finding the best deals for a specific product (and hopefully, your store will be the one they choose to buy it from).
You can add multiple products to your ad.
What do price extensions look like
The example above showcases a price extension that is viewed on desktop (on mobile, the extension is displayed as a carousel).
The store shows searchers different tea types that are closely related to their queries (I used the “buy tea online” search term), such as green and black tea.
Google automatically displays only one product price on desktop. However, that shouldn’t be an issue as interested users will click on the “More” button as I did.
One important note: you should only list the prices of products that are relevant to the search query.
If you wonder why I’m telling you this, here’s an example to show you what happens when you add irrelevant product prices:
My search query was “buy ray bans”.
However, the ad fails to display any prices for Ray Ban sunglasses. Only the headline includes the phrase “ray ban”.
Instead of sunglasses, the store lists products that are totally irrelevant to my search, such as dresses and boots.
If I were the advertiser who crafted this ad, I’d use the price extension to show only Ray Ban products or at least items that are closely related to the brand (e.g., sunglasses).
This can be accomplished by adding the extensions on the right level (ad groups vs. campaigns vs. account level).
How to add price extensions to your ads
You’ll find the option to create price extensions like the others (Ads & extensions menu).
After language, you have to specify that price extension type you want to use that can range from brands, product tiers and categories to events.
You can choose the currency you want to use with the extension as well as the price qualifier (e.g., from $10), but the latter step being completely optional.
While there’s no minimum number, you can add a maximum of 8 price extension items to your ad.
Each item has a header with a character limit of 25, a description (25 characters max.), a final URL, and an optional mobile final URL.
You also have to add the price value (e.g., $10), and you have the optional choice to add a unit after your price (e.g., $10 per day).
Like with the other, you have the option to add URL options for tracking, and advanced settings for scheduling and active hours.
Pro tip: Add popular products that are closely relevant to the search terms (as well as your ad) as price extension items to each and every of your ad groups to increase the CTR of your ads.
Remember the ad with the phone number earlier in this article?
That phone number was added using Google’s call extension.
Call extension is an easy, but amazing thing to add to your ad.
When your call extension shows, searchers can tap or click a button to call your business directly (or they can enter your phone number manually to call you).
According to Google, adding a phone number to your ad can significantly increase your CTR.
Google is right.
You can increase the trust of your searchers as well as its a must-have if your store offers phone support.
What do call extensions look like
Source: Search Engine Land
A call extension is one of the simplest ad extensions. In the ad above, you see a phone number displayed next to the headline.
And that’s all.
Simple, but effective.
How to add call extensions to your ad
Select call extensions from the “Ads & extensions” menu.
As this ad extension is pretty simple, you don’t have as many options as with other extension types to play with the settings.
Firstly, as the most important setting, you have to add the phone number you want to display in the extension as well as the country for that number.
The call reporting setting records data of your phone calls, including the time when they were made and received, the duration as well as the caller’s area code.
If you turn call reporting on (which you should), you can choose a conversion action to track call from the ads.
In case you don’t set your own, Google will choose “Calls from ads” as the default option.
You also have the option to tweak with advanced settings like in the case of other extensions.
Google recently also started showing call waiting times in mobile ads. here is an example from Away:
Pro tip: Displaying a phone number in your ad creates trust in your prospects as they may think that they can ask you or your customer service questions about your store and its products.
Structured snippet extensions
Using structured snippets is a great way to showcase additional information about your products in a dynamic way.
Showing on both mobile and desktop devices, structured snippets are displayed beneath your text ad in the form of a header (e.g., Brands) and values (e.g., Adidas, Puma, etc.).
The options for structured snippet headers are limited (you can choose from Google’s list), and each header type will only show when Google’s algorithm determines that it matches the intent of the searcher.
For example, if someone searches “buy apple lightning to USB cable 2m” is looking to purchase something very specific (a product and a brand that he knows or already researched).
He probably knows what he wants to buy and he is determined to purchase that product.
For this prospect, Google won’t necessarily show a structured snippet as he already knows what he is going to buy.
On the other hand, a prospect that looks to compare the best lightning cables for iPhones is discovering his product options and hasn’t decided (yet) on which item to purchase.
For this searcher, different product types, models, or brands a store is selling.
Google Ads allows you to add multiple data points (headers) so the search engine can display the most relevant structured snippet to the prospect that is based on his query intent.
You can choose from the following data points:
- Degree programs
- Featured hotels
- Insurance coverage
- Service catalog
What do structured snippet extensions look like
Let’s see an example of structured snippets:
My search query was “buy tea online” that triggered this ad.
As you can see in the image, Google displayed the different tea types, such as green, black, and matcha.
Are they relevant to my query intent?
If I wanted to purchase tea online, I’d be curious what types of tea a store is selling, and in case I’m satisfied with the tea types offered, I’d gladly click on the ad.
How to add structured snippet extensions to your ads
Inside “Ads & extensions,” select structured snippets.
When you are at the setup page, the first thing to set is the type and language of the header (data point).
When you’ve chosen one, type in the values for the header. Google recommends to include at least 4 values per header.
You can create multiple headers (which I’d recommend), and Google can show up to 2 structured snippets on desktop and a maximum of one on mobile and tablet devices.
After you are finished with your headers and their values, you can set scheduling, uptime, and mobile device preferences in the advanced settings.
Pro tip: As Google determines which structured snippets to show based on searcher intent (so it is not up to you to display your extensions to searchers), create as many relevant headers as possible to increase the relevancy of your ads.
You can also go granular with structured snippets for specific campaigns and ad groups.
If your ecommerce store has a physical location, then you should take advantage of this ad extension to generate more sales.
Location extensions allow you to harness the power of locations by showing your ads with your address, a map to your location, or the distance to your business for searchers.
This ad extension type works differently from the others; you pay for clicks that take your prospects to your site, but also for clicks that will give your searchers more details on your location.
Clicking this extension will take your prospects right to Google Maps that with your business’ location already inputted into the destination.
Location extensions can also show your phone number along with your location so prospects can easily call your business.
What do location extensions look like
Source: Search Engine Land
The location extension in the example shows the physical address and the phone number of the store as well as the open hours of the business.
That’s all the information a prospect needs to visit the store.
Searchers can choose between directly visiting your store after clicking on the extension or call your number as well as visit your website for more information.
For ecommerce businesses with a physical presence, your ad copy and your location extension with a phone number is a great chance to combine the effectiveness of the offline and online world to boost your revenue.
How to add location extensions to your ads
Setting up location extensions with your ads is a little different than the others.
After clicking the plus icon inside “Ads & extensions” and selecting location extensions, Google will direct you to a page where you have to link your Google Ads account with Google My Business.
You have two options: select a Google My Business account to use or request access to another Google My Business account.
After selecting your preferred option, click “Manage locations in Google My Business” that will allow you to edit locations and addresses for your store.
In case you have multiple locations, then select the one that’s most fit for your campaign.
After you have successfully connected your Google Ads account to Google My Business, your new location extension will be waiting for you to use inside the extensions tab.
Pro tip: Since you’re paying for each click on the extension, monitor how many you get and make sure these are worth it!
As we are heading towards the third decade of the 21st century, phone calls are becoming outdated.
Especially with so many apps focusing on instant messaging (e.g., Messenger, WhatsApp), people often find this mode of communication more convenient.
I don’t know about you, but in most cases, I prefer to read an email than have a call with someone.
It’s faster, easier, and more convenient as well as I have the time to think through everything before I tell someone something important.
And for prospects who are like this, Google’s message extension is a great way to get in contact with your business.
Message extensions let searchers who see your ad to send you text messages from their smartphones with one tap on your ad.
They can use messages to book an appointment, ask for more information on your store and products, request a service, get a quote, and more.
Personally, I haven’t found these extensions to be that effective for clients that I work with. But there are a couple of case studies floating around that show some positive results. So give them a spin to see if they work better for you.
Also, please note that message extensions only work on mobile devices.
By tapping on your ad, the messaging app will open on the device of the prospects with a pre-populated message that you create.
And you can take advantage of this mode of communication by providing users another convenient way to contact you.
What do message extensions look like
Message extensions will show beneath your ad copy with a message icon and a custom message you can leave there to prospects.
When searchers tap on your message extension, they will be redirected to their messaging app where they will send you an automatic, preset message.
How to add message extensions to your ads
Click on message extensions inside “Ads & extensions.”
On the setup page, you can select the user country code (where your extension will show) as well as the form of message delivery where Google will forward all prospect texts.
To set up the copy, you have to fill out the forms with your business name (limited to 25 characters), the extension text that will show in your ad (max 35 characters), the default customer message prospects will automatically send you when they contact you (100 characters maximum) as well as an optional auto-reply message with the same character limit as the default customer message.
You can set up message reporting to get data of your message extension’s performance.
When you are ready with all that, you can tweak with advanced settings then save your extension for it to go live.
Pro tip: If prospects haven’t replied back to your messages, be sure to follow those up to increase the answer rate.
Now that I’ve gone through all the essential manual ad extensions for your ecommerce store, it’s time to see three of the best automated extensions Google has to offer for advertisers.
How to enable automated extensions
The surprising thing about all automated extensions that all of them are turned on by default in every Google Ads account.
If for some reason, you might have turned them off, you can re-enable them by heading over “Ads & extensions,” click on the “Automated Extensions tab,” and click “Advanced options” inside the three dots icon on the right-hand side of the page.
On the next screen, choose the first option: “Use all automated extensions that typically boost ads’ performance”, and click “Done.”
How to disable automated extensions
Not many advertisers know that Google has turned on automated extensions by default.
This is a pretty sneaky move, because it removes control away from the advertiser and can show product or category pages you’d rather not pay to promote. (It’s not the first time Google has done something like this)
To disable these automated extensions, head to the same menu as in the last section (Ads & extensions > Automated Extensions > Advanced options), and select the second option (”Turn off specific automated extensions”).
After you click it, a list will appear with different automated extension types. Select the ones you’d like to disable and click “Done.”
Seller ratings extensions
When you are shopping online, do you prefer to buy from sellers that have great ratings from past customers?
I do as well as many others.
And if your store has decent customer ratings, then you should take advantage of this feature of your business.
Seller ratings extensions help to create trust with potential customers.
For seller ratings to show with your ads, you need to either use a review service that’s approved by Google or send a feed of their reviews.
Google uses the following sources to aggregate seller ratings:
- Review from your site that have passed through one of Google’s review partners
- Google Customer Reviews: Google’s free programme collecting post-purchase comments on behalf of advertisers
- Aggregated performance metrics from Google-led shopping research
- Google Consumer Survey ratings where Google collects data for certain domains and businesses
Besides the rating and number of reviews, Google often displays other information as well. Like in the ad above, Order accuracy. Or in the first ad of this section, they mention an estimated delivery time.
According to Google, seller ratings can show for your ads if your store has at least 100 unique reviews from the same country and a composite rating of 3.5 stars or higher.
Please note that the seller ratings extension is country-specific.
Therefore, in the case you have 50 ratings from Argentina and 70 from the United States, the extension won’t show for users from these two countries. However, if you have 10 ratings from Argentina and 110 from the United States (above 3.5 stars), the extension will be triggered for relevant searches in the US.
Seller ratings are the only ad extension that also works with Google Shopping.
Dynamic sitelink extensions
A dynamic sitelink extension is an automated ad extension that is similar to its manual brother, sitelink extensions.
Both displays sitelinks beneath your ad copy that, when searchers click on them, will take the prospects to different pages of your website.
The main difference between the two is that dynamic sitelinks give you less control over your ad extensions as it is totally up to Google which pages they decide to surface.
Dynamic structured snippet extensions
Remember structured snippets earlier in this article?
If yes, then you may know that structured snippets use data points with their values to show additional information about your business and products to the searchers (based on user intent).
In the case of manual structured snippet extensions, you had to add multiple headers with specific values to your ad.
However, you don’t have to do that with dynamic structured snippets.
As this ad extension is automated, Google analyzes your store and selects different data points (such as product types and brands) and shows them to searchers with relevant queries.
Like the other automated extensions, you’ll have less control over this what will show up compared to the manual structured snippets.
Analyzing the performance of your ad extensions
After you have all your ad extensions up and running, you have to see how they are performing as well as create new ones that perform better.
Head to the “Extensions” tab inside “Ads & extensions” to analyze the performance of manual extensions.
You can see the data Google gathered from the performance of automated extensions in the “Automated Extensions” tab.
How to “fix” the default reports
However, before you turn a statistician for the upcoming hours, I have to highlight a problem with default reports.
Default reports show you a combination of how your ads and extensions have performed, which is not a great way to measure performance.
You NEED to know the metrics that correspond to a specific extension. If they are grouped together a great ad or a well-performing ad group can skew the results of your ad extensions.
Therefore, you need to tweak your report a bit.
Firstly, restrict your view to only one extension at once. You can do that by setting a filter in the top left side of the page (e.g., sitelink extensions).
Also, you can set the “Click Type” segment to reflect the performance of your extension on actual clicks.
If you have finished setting that up, then your report should look like this:
For call extensions, you shouldn’t base your report on clicks as your goal with this ad extension type was to searchers click or tap on your store’s phone number (and call you).
So for call extensions, I’d recommend you to segment your report by conversions.
If you click on the “Segment” tab, you’ll see three settings for conversions. You can tweak around to select the best setting for you that will reflect the performance of your call extensions properly.
Pro tip: If some of your extensions do not show or have low impressions, then your issue is most likely that your budget or average position is too low.
To fix that, you need to consider a more aggressive bid for the low-performing extensions (and their ads).
Stepping up your ad extensions game
I hope this article has helped you in determining the best extensions to use with your ecommerce store’s ads.
While ad extensions are great to improve the relevancy of your ads increasing their CTR and quality score as well as your ROAS, remember to use them wisely.
Creating, managing, and analyzing ad extensions can be a lot of work, especially for busy ecommerce store owners.
Therefore, you should start using them on the campaign level and add more over time.