Liam Walsh
Liam is a Co-Director at Intelligency and heads up the agency's Digital Intelligence & Paid Social activity. Over the last decade, he has worked with brands from the world of sports such as Premier League clubs to entertainment such as Channel 4 and Disney.
If you run Google Ads campaigns on Target CPA or Target ROAS and any of them show as “Limited by
budget,” there is a change coming on 17th August that will directly affect your costs. Google is
updating the way its bidding system works for these campaigns, and for many ecommerce
advertisers, it will push actual performance closer to the targets they have set, whether those
targets were carefully considered or simply never updated. This is not opt-in. Google is applying it
automatically, and it will not adjust your targets or budgets on your behalf.
What Is Actually Changing
Currently, when a campaign is constrained by its budget, Google’s algorithm tends to buy the
cheapest conversions it can find within that cap, often delivering results well below the target you
set. A campaign with a £100 Target CPA might consistently convert at £50, simply because the
budget ran out before the system needed to reach further. After 17th August, Google will shift its
approach so that performance tracks closer to the stated target, even as budgets change. In plain
terms, your target stops being a ceiling you rarely touched and becomes the destination the
algorithm actively aims for. The change applies across Search, Shopping, Performance Max, Demand
Gen and Display campaigns.
Why This Matters for Ecommerce
For retailers running budget-capped Shopping or Performance Max campaigns that have been
quietly beating their targets, the practical effect could be a lower return on ad spend and higher cost
per conversion almost overnight. For businesses operating on thin margins, that drift can erode
profitability before it shows up clearly in reporting. Performance Max campaigns carry an additional
consideration: Google has indicated that traffic may shift between channels such as Search,
Shopping and YouTube as the system rebalances, so channel-level performance will need closer
attention in the weeks following the change.
What You Should Do Before 17th August
The first step is to pull every campaign marked “Limited by budget” that uses Target CPA or Target
ROAS, then compare actual performance against the stated target over the last 90 days. Any
campaign where actual results sit significantly inside the target is one that will move. From there,
you have three options: reset the target to reflect your real performance before the change kicks in;
raise the budget so the campaign is no longer budget-limited and can scale at your true target; or
consciously accept the drift toward target if you are comfortable with the efficiency trade-off.
Google’s Bid Target Adjustment Tool, which has been available in accounts since 6th July, allows you
to update targets based on recent performance in just a few clicks. The most important thing is to
make that call deliberately, campaign by campaign, before 17th August makes it for you.
