The myth that freezes spend
One of the most stubborn beliefs in paid search is that changing a cost target, or moving a daily budget by more than 20%, erases what Smart Bidding has learned. The result is a campaign nobody wants to touch, even when the job calendar, the margins and the season all say it should move.
On a recent episode with Ginny Marvin, Google Ads Product Liaison, product manager Tal Akabas addressed it directly. On a steady campaign, changing tCPA, tROAS or the budget does not trigger Learning status and does not erase the campaign's history.
What Google does underneath
The mechanism is simpler than the myth. Google's backend already holds bid landscape data for the campaign, so when the target moves, it can scale bids in proportion to the change instead of starting over. The history stays, and the system adjusts on top of it.
That does not mean nothing happens. Performance can still shift after a change, because bids and traffic move with it. Some changes do bring Learning back: a new or reactivated bid strategy, a change to the campaign's composition, or a significant change to conversion goals. For a brand new conversion campaign, Google advises starting with Maximize Conversions or Maximize Conversion Value.
Move it on a rhythm
The useful discipline is rhythm, not fear. Allow for conversion delay, and avoid changing targets more than once inside a single conversion cycle, so each move gets judged on its own result. Anchor conversion values and targets in real financials, like margins and customer lifetime value, rather than a number that simply feels safe.
The same thinking applies to the season. Akabas said you don't necessarily need seasonality adjustments for standard holiday spikes, because Google's year over year models already anticipate them. Save them for anomalies the system can't know about, such as an off-cycle sale or a discount much deeper than last year's. For a planned promotion, Promotion Mode, rolling out to Search and Performance Max, schedules a window with its own budget and bid changes, and it can be applied to existing steady campaigns.
What changes in your business
The owner, or whoever runs the ads, puts one review date per conversion cycle on the calendar. On that day they compare what the campaign brought in against the margins on those jobs, move the budget or the cost target once, and leave it alone until the next date. In between, a pacing alert or rule keeps watch: when spend runs ahead of the monthly plan, it warns the team, dials back the daily cap, or raises the tROAS target.
In the week, it shows up as fewer anxious debates about whether to touch the account, and a spend line that follows the business instead of the fear of breaking something. Winter and year-end budgets get set on purpose, with numbers the owner can defend, while the campaign keeps everything it already knows.