Every PPC manager knows the specific anxiety of scaling a winning campaign.
A campaign is capped at $100 a day. Its target CPA is set to $50, but Smart Bidding has settled at a pristine $35. Clients are happy, leadership is impressed, and the natural next step is obvious: increase the budget.
So the daily limit is raised to $500, and managers watch in real time as performance destabilizes, the algorithm loses its footing, and the actual CPA skyrockets past the $50 target.
For years, budget-limited campaigns using target-based bid strategies (Target CPA and Target ROAS) treated daily budgets as an artificial efficiency throttle. When the budget valve is opened, the algorithm’s bidding mechanics shift unpredictably.
Starting August 17, 2026, as mentioned in Google’s official documentation, Google is permanently changing this behavior. While much of the initial reaction in the PPC community has focused on lost “cheap conversions,” there is a massive strategic upside: Google is uncoupling the budget lever from the efficiency lever.
Here is what is actually changing under the hood, why it makes account scaling far more predictable, and how to prepare campaigns before the deadline.
The Historical Flaw: Why Scaling Budgets Used to Break Campaigns
To understand why August 17 is a long-term win, PPC managers have to look at how Smart Bidding previously handled budget-constrained campaigns.
Historically, if a campaign was marked “Limited by budget,” Smart Bidding didn’t just cap spend. It aggressively restricted its bidding behavior to capture only the absolute cheapest, highest-intent conversions available within that tight dollar limit.
This creates a misleading baseline. A campaign with a $50 target CPA that delivers $35 CPA is not necessarily “overperforming”; it is mainly buying a small, capped slice of the inventory, since the capped budget was avoiding using it in any other inventory. The issue is, once you increase this campaign budget and unlock more inventory, the smart bidding is forced to suddenly re-evaluate broader auction pools, which is not part of the campaign initial learning; this resulted in CPA spikes and performance instability, and also extended the re-learning period.
The August 17 Shift- Disconnecting budget and efficiency
After August 17, Google is forcing Smart Bidding to optimize strictly toward the target sitting in the box, regardless of whether the campaign is budget-constrained or fully funded.
Google’s official documentation illustrates this clearly: if a campaign has a $10 Target CPA but recent actual performance is $5, the post-August 17 algorithm will deliver closer to $10.
At first glance, that sounds like an efficiency penalty. In reality, it is a stabilization fix.
How is Google doing that? By separating the connection between efficiency and budget:
- The Bid Target dictates efficiency and margin.
- The Daily Budget dictates the volume ceiling.
When these two levers operate independently, scaling becomes linear. If the team increases the budget on a campaign that is locked into a $35 target, the algorithm will capture more volume at that $35 target, rather than wildly shifting its bidding parameters trying to figure out what efficiency level the team actually wanted.
So, which campaigns will be impacted?
Not every campaign on an account operates under these new rules. Understanding where the boundaries lie ensures the team’s audit focuses on the right structures.
| Campaign Type / Category | Bidding Strategies Impacted | Post-August 17 Behavior |
| Search, Shopping, Performance Max, Demand Gen, Travel | Target CPA, Target ROAS, Target CPC (Demand Gen) | Changes: Will strictly deliver toward the stated target, eliminating budget-cap overperformance. |
| Display & Hotel | Target CPA, Target ROAS | No Change: Already operate under this strict target behavior. |
| App Campaigns, Video Reach, Video View (VVC) | Target CPA, Target ROAS / Cost-Per-View | Retain historical bidding behavior. |
| Manual Bidding, Max Conversions, Max Value | Manual CPC, Target Impression Share | Unaffected by target-based bidding changes. |
How to prepare? Finding the silver lining
Yeah, I know this is a cliché, but I can’t help looking at the bright side; after years of carefully tweaking scale so we wouldn’t hurt performance, knowing we can rely on more stable results while scaling is also actually a big growth opportunity. However, because Google will not automatically adjust bid targets, doing nothing is an active choice to let the CPAs trend upward toward whatever legacy numbers are sitting in the settings.
So, if you want to turn this update into a scaling opportunity, follow this four-step transition framework using Google’s Bid Target Adjustment Tool (available in accounts since July 6):
1. Access the Bid Target Adjustment Tool
Open the notification in a Google Ads account to launch the Bid Target Adjustment Tool (rolled out July 6). Google automatically populates this view with any campaign that hit a “Limited by budget” constraint over the last 12 months—meaning teams don’t have to dig through historical status logs. (If you want to manually cross-check your account, filter your campaign table by Search Lost IS (budget) > 0% over a 12-month date range).
Note: Also compare it against the last 30 days of performance to make sure this target is realistic
2. Change or maintain the current CPA bids
- Stale Targets (The Fix): The $50 target was typed in during campaign launch six months ago, and performance naturally settled at $35. Action: Use the Bid Target Adjustment Tool to click “Apply” and shift the stated target to $35. This locks in your current efficiency and creates a clean baseline for future budget increases.
- Keep Targets: In case the bid should be higher than the current CPA setup, for example, if your campaign is not limited by budget, and the higher CPA does reflect your business goal, and you are looking to scale and reach a broader audience, keep the bids as they are.
3. Respect the Conversion Cycle Window
Keep in mind that smart bidding will need 1-2 conversion cycles, so it will be re-stabilized after the bid adjustment. If the account is operating with a 1-week sales cycle, you should take this into account and make sure you change the bid in advance; that way, the conversion will be stable in time for the change.
4. Incrementally reality check:
The campaign that is overperforming with a much lower CPA than the target often targets the low-hanging fruit like brand searches. Use this change to reevaluate if this campaign generates actual incremental value and make any adjustments needed
The Bottom Line
August 17 is not the end of efficient Smart Bidding; it is the end of accidental efficiency driven by budget bottlenecks.
By pulling stale targets back down to match actual performance today, PPC managers eliminate the risk of unwanted CPA drift. More importantly, they set accounts up for a future where increasing a budget actually does what it was supposed to do all along: scale the results predictably without breaking what worked.
