Foreword
Historically, a campaign that was Limited by Budget often outperformed its stated target, because it could afford to enter only the most efficient auctions available. From 17 August, that headroom shrinks. Smart Bidding will hold more closely to the Target CPA or Target ROAS you've set, even as budgets grow.
In practice:
If a campaign has been running efficient and Limited by Budget for a while, the reported efficiency you've grown used to was partly a side effect of budget scarcity, not purely the target doing its job. Once that scarcity effect goes, the target is what you get. That's worth knowing before a board pack cites last quarter's CPA as the baseline for next quarter's spend increase.
Three things, in order:
This is also a reasonable moment to ask a harder question: is the target itself right, or was it set to fit a budget-constrained world that's about to disappear? We've said it before and it holds here too: adding budget to a broken structure just makes the hole more expensive. A tighter Smart Bidding algorithm won't fix a target that was never grounded in margin in the first place.
It doesn't change the case for POAS over ROAS wherever margin data allows. If anything, a stricter link between target and delivery makes the metric you're targeting matter more, not less. A precisely-hit ROAS target on the wrong metric is still the wrong outcome, just more reliably wrong.
Not sure which of your campaigns are exposed before 17 August? Get in touch and we'll take a look. You'll get a straightforward view on whether the target needs changing, the campaign does, or neither.
