Blog: Google’s August 17th Bidding Update: Why Your CPA Is About to Rise (and How to Stop It)

For a while, some Google Ads accounts have been beating their own targets — a $10 Target CPA campaign settling in at $5, a Target ROAS goal cleared without anyone touching a setting. Most advertisers filed that under “good problem to have” and moved on. 

Starting August 17th, 2026, Google is changing the bidding behavior that made that possible, and the accounts currently coasting on it are about to see their numbers move. 

Most of the coverage of this change treats it as a deadline: update your targets in the Bid Target Adjustment Tool, or watch your CPA rise. That’s true, but it’s the smaller story. The bigger one is that the gap you’ve been benefiting from wasn’t a mistake — it was room Smart Bidding used to test and explore on your behalf — and this update closes it. 

Here’s what’s actually changing, why the “overperforming” target was never free, and how to decide what your bidding strategy should do next, rather than just resetting a number to clear the deadline.

What Is Google’s August 17th Bidding Update?

On August 17th, 2026, Google is changing how target-based bid strategies behave on campaigns marked “Limited by budget.” Today, when a budget-limited campaign runs Target CPA or Target ROAS, Smart Bidding often delivers better than the target you set because it’s concentrating a capped budget on the cheapest, most efficient auctions it can find. 

After August 17th, that stops. Budget-limited campaigns will optimize consistently toward the number you actually entered, including when you adjust budgets.

Google’s own stated example makes the stakes concrete: if your Target CPA is $10 but your recent actual CPA has been running at $5, your campaign will start delivering closer to $10.

Why Is My Google Ads CPA About to Go Up?

Because the gap between your stated target and your actual performance was never a permanent feature of your account. It was a byproduct of how Smart Bidding handles a constrained budget. 

When spend is limited, the algorithm doesn’t need to spend all the way up to your target to hit your budget cap, so it skims the cheapest available conversions and leaves the rest of the auction alone.

After August 17th, that skimming behavior goes away. The algorithm optimizes toward your target as configured, not toward the cheapest outcome it can find under a spending cap. If you don’t touch anything, your real-world CPA drifts up (or your ROAS drifts down) to match the number you set, possibly months or years ago.

Which Campaign Types Are Affected by the August 17th Change?

The update applies to any campaign using a target-based bid strategy that can be marked “Limited by budget”:

• Search
• Shopping
• Performance Max
• Demand Gen (including Target CPC, which functions as the target-based strategy for this campaign type)
• Travel

Display and Hotel campaigns already operate this way, so nothing changes for them. App campaigns and Video reach/view campaigns are excluded entirely.

Worth noting for anyone running Performance Max or Demand Gen: Google has said advertisers may see traffic shift between channels within these campaign types as the system rebalances toward the target. A tighter CPA isn’t the only thing that moves; where your budget actually gets spent can shift, too.

Was Your “Overperforming” Campaign Actually a Mistake?

Most coverage of this update treats the overperforming target as an error to be corrected: set your target above where performance settled, and the discrepancy is a loose bolt to tighten before the deadline. That framing misses what was actually happening.

A target set above your true cost goal gives Smart Bidding room to work. It can bid into less certain auctions, test new audiences, and surface conversions it wouldn’t touch under a tighter constraint, and over time, some of that exploration turns into the cheaper, durable performance you’ve been benefiting from. The “overperforming” number was slack you were, knowingly or not, using to let the algorithm find things a tighter target would never let it try.

August 17th closes that room. Any account currently coasting on a gap between target and actual performance should assume the exploration budget that produced it is going away.

Why Google’s Answer Is “Raise Your Budget” And Why That Deserves Scrutiny

Google’s framing for this update is predictability: campaigns will perform more consistently at your stated target, including when you increase budget, which makes scaling easier to plan around. 

That’s a real benefit, and it’s true on its own terms.

It’s also an answer that happens to serve Google. Once a budget-limited campaign can no longer significantly beat its target, the most direct lever left for growing volume is raising the budget — spending more to get more, at a target you now have to actively manage. 

That’s a reasonable option. It’s not the only one, and it’s worth noticing that it’s the option Google’s own tooling and messaging point you toward first.

Treat “raise your budget” as one input to a decision, not the decision itself. The right response to this update depends on what you actually want from the campaign — protect current cost efficiency, accept a higher CPA in exchange for volume, or hold and watch — not on which lever Google made easiest to pull.

How to Prepare for the August 17th Bidding Change

1. Audit every budget-limited campaign on Target CPA, Target ROAS, or Demand Gen Target CPC. Pull the gap between stated target and trailing actual CPA/ROAS for each one.
2. Decide deliberately for each campaign, rather than defaulting to one approach across the account:
   1. Hold the target and accept CPA rising to meet it, if the target reflects what you’re actually willing to pay.
   2. Lower the target to match recent performance, if you want to protect the efficiency you’ve been getting.
   3. Treat the gap as a real growth signal and raise the budget with a specific hypothesis for what that spend should buy.
3. Use the Bid Target Adjustment Tool as one input, not the final word. It shows recent performance; it doesn’t know your margins, your goals, or how much volatility you can tolerate this quarter.
4. Build in a recheck cadence. The gap between target and actual reopens as performance moves over time. Fixing it once in August doesn’t mean it should stay fixed.

Turn This Deadline Into a Strategy Decision

The deadline framing that’s dominated coverage of this change — update your targets or lose performance — isn’t wrong, but it’s incomplete. The bigger shift is that the era of banking efficiency on a capped budget, without ever having to explain why your numbers looked the way they did, is over. 

Campaigns that come out ahead after August 17th won’t be the ones that happened to have a favorable gap between target and actual performance. They’ll be the ones with a target-and-budget strategy someone actually chose and can defend.

That’s the work worth doing before the 17th: not just resetting a target to clear a deadline, but deciding, campaign by campaign, what you actually want your bidding strategy to do next.

Not sure which of your campaigns are exposed, or what the right call is for each one? Silverback works with advertisers to turn moments like this into a real bidding strategy, not just a settings update. Get in touch with our team to review your accounts.