Most ecommerce stores try to have their cost per acquisition (or CPA) as low as possible.
So using a bidding strategy that uses CPA as an explicit goal for your Google Ads campaigns sounds like a match made in heaven.
But is the Target CPA bidding strategy really the best option?
In this article, we’ll take a closer look at how this strategy works, when to use it in your campaigns, and what target you should use.
Table of Contents
What is Target CPA Bidding?
Target CPA, or target cost per action, is an automated bidding strategy where you tell Google Ads how much you’re willing to pay for a conversion.
The cost per action in a campaign is calculated with this formula:
Average CPA = Ad spend / number of conversions
When you set your target CPA, Google will automatically determine the cost per click for each keyword or product.
While CPA stands for cost per action, we’ll use it interchangeably with cost per sale or cost per conversion in this article.
How Does Target CPA Work in Google Ads?
Google Ads uses your campaign’s historical conversion data and real-time signals (e.g. device type, location, browser, time of the day, browsing history, etc.) to find users that are more likely to convert.
To get this to work, you need to set up conversion tracking and have a decent number of conversions in your campaign. (We’ll talk more about this later in the article).
Google will try to deliver conversions to the average CPA. So naturally, you will see some conversions that might be more expensive, while others will be cheaper.
The target that you choose to use will also depend on how many conversions you’ll get (= conversion volume). If you go very aggressively and set a low target CPA, you will get few conversions. If you set a very high target CPA, Google will have a much easier time finding conversions and you will see more of them.
When to Use Target CPA?
You can use Target CPA bidding for Search, Display, Demand Gen, and Performance Max
Target CPA is not available for Standard Shopping campaigns. For a similar automated bid strategy for Shopping campaigns, I recommend taking a look at Target ROAS.
You can use Target CPA as a standard or portfolio bid strategy to optimize your bids across multiple campaigns.
In addition to setting up conversion tracking, you must have at least 15 conversions in the last 30 days in your campaign (not your account) to use Target CPA.
However, Google recommends having a minimum of 30 conversions in the past 30 days for Target CPA to perform well with your campaign.
This shouldn’t come as a surprise.
Target CPA is a Smart Bidding strategy that sets bids automatically via machine learning algorithms to get you the most conversions at or below your target cost per conversion.
The more conversion data you have, the better insight the algorithms have into what worked for you in the past. This helps Google to optimize your campaigns and achieve better performance in the future.
When not to use Target CPA?
With Target CPA, Google decides how much to pay for each click. So if there is some reason why you always want full control, stay away from automated bidding.
One of the biggest reasons why you wouldn’t use Target CPA as an ecommerce business is that it doesn’t take the conversion value into account.
Let’s say order A has a CPA of $10 and brings in $100 in revenue. Order B might also have a CPA of $10, but bring in $200.
If the products in both orders have similar margins, a retailer probably wants more orders like B.
Target CPA doesn’t make this distinction. Luckily, there is Target ROAS bidding to save the day!
You should also hold off on Target CPA if your campaign is brand new with no conversion history. Forcing Google to hit a target before it has enough data will restrict delivery. Start with Maximize Conversions first, then switch to Target CPA once you have 30+ conversions per month and your CPA is relatively stable.
The same goes if your conversion tracking is unreliable. If your conversion tag fires inconsistently, counts duplicates, or tracks low-quality events (like page views instead of actual purchases), Target CPA will optimize toward the wrong signals. Bad data in = bad bids out.
And if your CPA is still fluctuating wildly day to day, adding a target will either choke traffic or overshoot your goal. Wait until you see a more consistent pattern before switching.
Target CPA Best Practices
While Target CPA can get you good results, below are a few recommendations to get the most out of this bidding strategy.
Set Up Realistic Target CPA Goals
To start with any automated bidding strategy, you need to have a firm grasp of your CPA in Google Ads.
That means running your campaigns on manual bidding for a while to get an idea of your baseline numbers.
Most experienced store owners have a good idea about their break-even CPA. But when presented with the opportunity to set a max CPA, many will set a CPA well below that.
Let’s say your break-even CPA is $25. And hitting a sale of $20 means a healthy profit. So you could set the target CPA at $20.
But it’s not because you want to hit a certain CPA that Google can (or wants to) deliver.
Let’s say that before you were running your campaigns using Manual CPC and that over the course of a couple of months, you were hitting a CPA of $24.
As your historical cost per acquisition is significantly higher than your goal, setting your target CPA at $20 is way too aggressive. And you will starve your campaigns of traffic. This results in hitting that target but only selling 10 instead of 100 units at that cost per sale.
So the only way to come up with a realistic number is to have a historical performance that’s in line with the number you want to hit. Then over time, you can experiment with decreasing the CPA.
Pro tip: When checking whether you’re hitting your target, don’t just compare your actual CPA to the target you set. Instead, look at the “Average Target CPA” metric in your bid strategy report. This metric accounts for device bid adjustments, ad group-level targets, and any changes you’ve made over time. It gives you a more accurate picture of what Smart Bidding is actually optimizing toward.
Budget Sizing for Target CPA
Your daily budget plays a bigger role in Target CPA performance than most advertisers realize.
If your budget is too close to your target CPA, Google won’t have enough room to test different auctions and find the conversions you need.
Google recommends a daily budget of at least 2x your target CPA. So if your target CPA is $50, your daily budget should be at least $100.
In practice, I’d recommend going even higher if possible, especially when you’re first enabling the strategy. A daily budget of 3x to 5x your target CPA gives the algorithm enough room to learn which auctions convert without running out of budget too early in the day.
If your budget is too tight, you’ll often see Target CPA underspend or stop delivering entirely. Google would rather not spend your budget than overshoot your target.
Keep in mind that Google can spend up to 2x your average daily budget on any given day (while staying within your monthly budget limit). Don’t panic when you see a single high-spend day. That’s normal with automated bidding.
The Learning Phase
Beware that every change (budget, bidding strategy, new products, etc.) to a campaign that uses an automated bidding strategy will need some time to adapt. You’ll see this displayed in the Campaign status column as “Eligible (Learning)”.
This period is called the learning phase, in which Google’s machine learning algorithms familiarize themselves with your campaigns.
The learning state lasts approximately seven days. If you continue to see the learning status after two weeks, you should check whether your conversion settings are misconfigured (take a look at Google’s page to fix the issue).
As it takes some trials and errors for Google to get things right while starting out with Target CPA, you will likely notice that your campaigns perform worse than usual.
This could come with a fall in daily spending and conversion rate as well as a CPA increase.
However, unless you see something very unusual, it’s best to wait through the learning period without making significant changes to your campaign.
You don’t want to pull the plug before you see the real results.
A few things that help the learning phase go smoother. First, consolidate your ad groups so each one gets enough conversion data. Spreading thin across too many ad groups starves each one of signal.
Second, avoid changing the target mid-learning. Every time you adjust the target CPA, budget, or conversion goals, you reset the learning phase. Make your changes, then hands off for at least 7 to 14 days.
Third, if you’re switching from Maximize Conversions and already have solid conversion volume, the learning phase will be shorter. Google already has data to work with.
Unblending Your Campaigns
If you want Google to be effective at delivering your Target CPA, you need to “unblend” your campaigns.
This means that you group keywords or products into a campaign that generates similar results.
Mixing branded searches (with a low CPA) with unbranded searches (with a high CPA) in the same campaign might result in something in between, which makes it hard for Google to find more potential conversions at that price.
The same logic applies beyond branded vs. unbranded. Don’t mix competitor terms, generic terms, and bottom-of-funnel product terms in the same campaign. Each group will have different conversion rates and CPAs, so they need separate targets.
Also, stick to one primary conversion action per campaign. If you’re optimizing for both purchases and newsletter signups in the same campaign, Target CPA will average across them. The algorithm won’t know which one matters most. Pick one high-signal action (purchase, qualified lead) and make that your primary conversion.
In some campaign types (like Demand Gen), you can also set different target CPAs at the ad group level. This is useful when ad groups within the same campaign have different conversion economics.
Make Sure Your Conversion Tracking is Right
Target CPA is only as smart as the conversion data you feed it. If you’re tracking the wrong actions or tracking them incorrectly, the algorithm will optimize toward the wrong outcomes.
The most common problem I see is advertisers optimizing for the wrong conversion action. For ecommerce, you should be tracking completed purchases. For lead gen, it’s a qualified form submission. Avoid optimizing for micro-conversions like page views, button clicks, or “add to cart” events. These inflate your reported conversion count while diluting actual quality.
Google Ads lets you set conversion actions as “primary” (used for bidding optimization) or “secondary” (tracked for observation only). Make sure only the conversions that represent real business value are set as primary. Everything else should be secondary so it doesn’t confuse the algorithm.
Check your conversion tags at least once a month. Make sure they’re still firing correctly, not double-counting, and arriving on schedule. A broken or misconfigured tag will quietly wreck your Target CPA performance without any obvious warning signs. If you’re new to this, check out our guide on how to set up conversion tracking.
Landing Pages Matter More Than You Think
No bidding strategy can overcome a bad landing page. Target CPA sets the right bids to get people to your site, but what happens after the click is entirely up to you.
If your Google Ads click-through rate is strong but your conversion rate is weak, that’s almost always a landing page problem. Not a bidding problem.
A few things to check. Is the landing page relevant to the keywords and ad copy? If someone clicks an ad for “running shoes” and lands on a generic homepage, they’ll bounce. Does the page load fast on mobile? Is there a clear, single call to action? Is the page asking for too much upfront (long forms, required account creation)?
Improving your landing page conversion rate directly improves what Target CPA can do for you. A higher conversion rate means Google can bid more aggressively in auctions while still hitting your target.
How Bid Adjustments Work with Target CPA
If you’re switching from Manual CPC, you might be used to setting bid adjustments for things like location, time of day, audience segments, and devices. Here’s what changes with Target CPA.
Most bid adjustments are ignored. Under Smart Bidding, Google handles all the signal-based optimization itself. Location, time of day, and audience bid adjustments from your Manual CPC days no longer have an effect. Google is already factoring these signals into every auction.
Device bid adjustments are the one exception. With Target CPA, device adjustments still work, but they modify your CPA target, not your bids. For example, if your target CPA is $10 and you set a +40% device bid adjustment for mobile, your effective target CPA on mobile becomes $14. You can also set a -100% device adjustment to stop showing ads on a specific device entirely.
If you’re moving from Manual CPC to Target CPA, clean up any leftover bid adjustments. The device ones will still apply and might skew your targets unintentionally. The rest will just sit there doing nothing.
Scaling Your Target CPA Campaigns
Once Target CPA is working well and hitting your targets, the natural next step is to scale. But scaling needs to happen gradually.
The most important rule: increase budget before lowering the target. If you’re seeing good results and want more volume, give the campaign more budget first. This lets Google find more auctions at your current CPA level. Only after volume stabilizes should you experiment with lowering the target.
Increase budgets by 20 to 30% at a time, then wait 1 to 2 weeks for performance to stabilize. Jumping from a $100/day budget to $500/day overnight forces the algorithm to chase a much larger pool of traffic, and that usually leads to a CPA spike.
You can also use portfolio bid strategies to scale across campaigns. Instead of managing Target CPA campaign by campaign, a portfolio strategy lets Google balance spend across multiple campaigns to hit your overall CPA goal. Stronger campaigns absorb more budget while weaker ones get less.
What Are the Pros and the Cons of Target CPA?
In what follows, you can find the pros and cons of the Target CPA bidding:
| Pros | Cons |
| Bid automation saves you time | Loss of control of bids for keywords and products |
| Great for “simple” conversions: similarly priced products or lead gen | Not the best fit for ecommerce businesses with diverse products prices. |
| Helps maintain consistent CPA as you scale | Requires sufficient conversion volume (30+/month) to perform well |
| Uses real-time auction signals that humans can’t process manually | Most traditional bid adjustments no longer apply |
Going Deeper on Google Ads
While this article covers a lot of ground about one important aspect of running your Google Ads campaigns, it barely scratches the surface of what it takes to win with Search and Shopping campaigns.
That’s exactly why I combined two of our courses, Search Ads Success and Google Shopping Success into a Google Ads Success bundle.
It covers everything I’ve learned from running these campaigns for the past 12 years, and much more.
If you want to learn more, I’d love for you to check it out!
On with the article 👇
How to Set Up Target CPA in Google Ads?
You can add Target CPA directly to a campaign by going into a campaign’s settings, expanding the “Bidding” section, clicking “Change bid strategy”, and selecting Target CPA from the list.
For Search campaigns, you may also see this as “Maximize Conversions” with an optional target CPA field. Setting a target CPA within Maximize Conversions behaves exactly the same as the standalone Target CPA strategy. Google uses the same algorithm either way.
If you’re switching the bidding strategy on an existing campaign, Google will come up with a recommended value, like in the screenshot above.
If you’re starting a new campaign, you’ll determine the CPA you want Google to use as its target.
Capping CPC with a portfolio bid strategy
One big downside to using target CPA is that you let Google decide how much to pay for a click.
To make sure things stay reasonable, you can add an extra safeguard with some called a portfolio bid strategy.
The idea behind this is that you can use a single bid strategy and apply it to multiple campaigns. But you can also use it on a single campaign.
To access this option, go to Tools & Settings > Bid strategies. Click the “+” icon and select Target CPA. Then click on “Advanced options”.
Here you can set optional maximum and minimum bid limits.
These limits give you additional control, but it removes some of the freedom Google might need to dial in its algorithms.
Bid limits only work for portfolio Target CPA strategies, and you can’t use the feature for Display-only campaigns.
While maximum bid limits prevent Google from paying CPCs above your rates, it’s possible for the algorithms to set cost per click below the minimum cap due to smart pricing.
One thing I’ve noticed when switching to automated bidding: Google sometimes gets eager with CPCs. You might be used to paying $1.50 per click on average, and then Google starts charging $5 or $9 for a click. That can feel excessive. And it usually is.
That’s why I’ll often start with a portfolio bid strategy with a max CPC cap on a single campaign, just to keep things reasonable in the first few weeks. Over time, I’ll loosen or remove the cap as Google settles in.
That said, Google recommends against bid limits because they can prevent the algorithm from bidding enough in the auctions where conversions are most likely. Use them as training wheels, not as a permanent setting.
What to Do When Target CPA Isn’t Working
Sometimes Target CPA just doesn’t deliver the results you expected. Before switching to a different strategy, work through this checklist.
1. Check your target against your historical CPA. If your actual CPA over the last 30 days is $80 and you’ve set a target of $40, you’re asking Google to cut costs in half overnight. That’s too aggressive. The algorithm will choke traffic rather than overspend. Raise the target to within 10 to 20% of your historical CPA and give it time to optimize.
2. Verify your conversion tracking. This is more common than you’d think. Check that your conversion tags are firing correctly, not double-counting, and that no recent changes have broken or reduced reported conversions. If Google thinks conversions dropped, it will pull back on spending.
3. Wait out the learning phase. If you just enabled Target CPA or made significant changes, give it at least 7 to 14 days before judging results. Performance will be volatile during this period. Making further changes mid-learning only resets the clock.
4. Review your budget. If your daily budget is less than 2x your target CPA, Google may not have enough room to find conversions. Increase your budget to at least 2 to 3x your target CPA.
5. Confirm you’re optimizing for the right conversions. Check which conversion actions are set as “primary” in your campaign. If you’re accidentally optimizing for low-value actions (page views, button clicks), your reported CPA will look fine while actual business results suffer.
6. Check your landing page. A declining conversion rate on your landing page will make it harder for Target CPA to hit your target. The algorithm can bring the right people, but if they’re not converting on the page, costs will rise.
7. Remove or loosen bid limits. If you’ve set maximum CPC bid limits in a portfolio strategy, they may be preventing Google from bidding enough to win the auctions that actually lead to conversions. Try loosening or removing them as a test.
If you’ve worked through all seven items and Target CPA still isn’t performing, consider switching back to Maximize Conversions (without a target) to let Google optimize freely. Then reintroduce a target once performance stabilizes.
Target CPA vs. Target ROAS vs. Maximize Conversions
With so many bidding options, it’s easy to mix up Target CPA with similar Smart Bidding strategies like Target ROAS and Maximize Conversions.
Learn more about How to use Smart Bidding in Google Ads.
To eliminate confusion, I’ve collected the most important aspects of the three automated bid strategies in the table below:
| Target CPA | Target ROAS | Maximize Conversions | |
| Bid Strategy Type | Smart bidding | Smart bidding | Smart bidding |
| Goal | Maximize conversions at or below your target CPA | Maximize conversion value to achieve an average return on ad spend as your target ROAS | Get the most conversions within your daily budget |
| Supported Campaign Types | Search, Display, Performance Max | Search, Display & Shopping campaigns | Search, Display, Performance Max & Demand Gen campaigns |
| Options For Control | Target CPA to keep average cost per acquisition at or below your rate. Bid limits (portfolio only): max and min CPC caps | Target ROAS to keep return on ad spend at or above your rate. Bid limits (portfolio only)Optional Target CPA to add a cost-per-conversion guardrail | Optional Target CPA to add a cost-per-conversion guardrail |
| Best For | “Simple” conversions (ecommerce, lead gen) Ecommerce stores with only a few or similarly priced products | Ecommerce stores with a decent conversion history Advertisers seeking to ensure that their campaigns remain profitable | Campaigns starting out on automated bidding. Campaigns where you want maximum volume without strict cost control |
For Search campaigns, Google also offers “Maximize Conversions” with an optional target CPA field. When you set a target, it behaves identically to the standalone Target CPA strategy. The key difference: Maximize Conversions without a target will try to spend your full daily budget to get as many conversions as possible, regardless of cost. Maximize Conversions with a target (or standalone Target CPA) prioritizes efficiency and may leave budget unspent if it can’t find conversions at your target price.
What is a Good CPA for Google Ads
Now that you’ve made it this far in the article, it’s time to get practical and decide how much your target CPA should be.
First, let me say that the “best” CPA doesn’t exist.
Here are two ecommerce CPA benchmarks from our research:
- Average CPA for Search Ads: $45.27
- Average CPA for Display Ads: $65.80
- Average CPA for Shopping Ads: $38.87.
While these are helpful in understanding where the market is at, it won’t be as relevant to your situation.
So let’s uncover what your ideal target CPA should be:
- Unit economics: if you look at your costs, what’s your break-even CPA? What’s the CPA that includes the necessary profit?
- Stage of the business: is the business focused on maximizing volume? Or is overall profit the main concern?
- Campaign performance: if your campaign currently can’t hit a certain CPA, it will be even harder to adjust it downward
Set your initial target CPA at or slightly above your average CPA from the last 30 days. About 10 to 20% higher is a safe starting point. This gives the algorithm room to optimize without choking traffic. Once performance stabilizes (after 2 to 4 weeks), gradually reduce the target in small increments.
Trying to jump straight to your ideal CPA from day one is the most common mistake I see.
Seasonality Adjustments
If you have a short, predictable promotional window, like a Black Friday sale or a flash discount, you can use Google’s seasonality adjustment feature to tell Smart Bidding that conversion rates are about to change temporarily.
This is useful because Target CPA’s algorithm learns from recent data. If your conversion rate suddenly spikes during a sale, the algorithm may not react fast enough on its own. A seasonality adjustment gives it a heads up.
Seasonality adjustments work best for short events (1 to 7 days). Leaving them on for extended periods can actually hurt performance. You set the expected conversion rate change as a percentage, for example “conversion rate will increase 50% during this 3-day sale.” The adjustment automatically expires, so you don’t need to remember to turn it off.
You can set seasonality adjustments under Tools & Settings > Bid Strategies > Advanced Controls.
How to Use Target CPA Effectively in Google Ads
Target CPA bidding will try to get you the most conversions at or below your cost per acquisition goal.
So if you have a good idea of your baseline numbers, and sell similarly priced items, it can be an excellent bidding strategy to try out.
However, it’s important to follow Target CPA’s best practices to get the best results and avoid issues like starving your campaigns from traffic.
Here’s a quick recap of the most important points: make sure your conversion tracking is accurate and tracks the right actions. Set your target based on historical data, not wishful thinking. Size your daily budget at 2 to 5x your target CPA. Give the learning phase at least 7 to 14 days before making changes. Structure campaigns around similar-intent keywords with one primary conversion action. Don’t forget about your landing pages. And use the troubleshooting checklist above if performance isn’t where you want it.
