Google explains what advertisers should expect from Smart Bidding changes

Google’s upcoming Smart Bidding update aims to make campaign performance more predictable by ensuring Target CPA and Target ROAS are respected regardless of budget constraints, a shift that could change how advertisers manage budget-limited campaigns.

What’s happening. Ahead of the Aug. 17 rollout, Google Ads Liaison Ginny Marvin addressed advertisers’ biggest questions about the update, emphasizing that bid targets will become the primary lever for controlling efficiency, even when campaigns are limited by budget.

Under the new behavior, campaigns that have been consistently outperforming their Target CPA or Target ROAS will begin optimizing toward the actual target set in the campaign, rather than exceeding it because additional budget isn’t available.

Performance swings. Google says the change is designed to reduce the performance swings advertisers often experience after increasing or decreasing campaign budgets.

Previously, budget changes could force Smart Bidding to readjust from the efficiency it had been achieving back toward the campaign’s stated target, creating temporary volatility. Google says the new system should make those transitions more stable because the bidding target remains consistent regardless of budget.

What won’t change. The company also noted that campaigns without budget constraints will not be affected, as Target CPA and Target ROAS already determine spending and efficiency in those scenarios.

Why we care. Budget-limited campaigns may behave differently after Aug. 17, particularly if their actual CPA or ROAS has consistently outperformed the target set in the campaign. Advertisers should review campaigns where there’s a significant gap between target and actual performance and decide whether bid targets still reflect current business goals.

Google has also introduced in-account notifications and a review tool to help advertisers identify campaigns that may need target adjustments before or after the rollout.

The bottom line. After Aug. 17, Smart Bidding targets, not budget constraints, will play a larger role in determining campaign efficiency. Advertisers who rely on Target CPA or Target ROAS should audit their settings now to avoid unexpected performance shifts.

Dig deeper. Community Q&A: August 17 bidding update