Switching agencies is where paid search usually stalls. This account changed hands heading into peak season, and return on ad spend has beaten the prior year every month since.
The situation
The client is an established consumer brand with Google Ads as a core revenue channel. In spring 2026 the brand moved its paid search program from its previous agency to a new one, heading into its biggest selling season.
Agency transitions are where paid search accounts usually stall. Campaign history gets orphaned, structures get rebuilt from scratch, and revenue dips while the algorithms relearn. With peak season weeks away, a dip was not acceptable.
The challenge
The transition audit found real problems under the hood. The account leaned heavily on Google’s automated, AI-driven campaign formats, which were delivering a weaker return than standard search, the campaign type quietly carrying the most reliable results. Non-brand search was underdeveloped. And two competing purchase-conversion sources, one from analytics and one from a tag-management tool, were feeding Google conflicting signals about what a sale even was.
So the job was two things at once: keep the account spending and learning through the transition, and fix the foundation without pausing to do it.
The solution
A transition with no dark period
Instead of flipping a switch on day one, the budget transition was phased across the first month: the previous structure wound down as the new one ramped, so the account never stopped spending or learning. That first month closed with ROAS up roughly 35% year over year, in the middle of the transition itself.
One source of truth for conversions
Before touching a bid, the conflicting purchase goals were resolved so bidding optimized to a single, clean purchase signal. Smart Bidding is only as good as the conversion data feeding it, and this fix gave every later change a solid floor to land on.
A structure with clear lanes
Brand was split from non-brand. Evergreen Performance Max (PMax) and standard search each got their own campaigns and budgets instead of competing inside one. Distinct product lines were separated so no line was funded on another’s economics. Seasonal promotions got standalone campaigns rather than being buried inside asset groups, live within days of being scoped.
Bid strategies proven, not assumed
Bid strategies were tested head to head rather than trusted by default. In the clearest test, Target ROAS returned more than three times what Maximize Conversions managed on comparable traffic. When Google’s August 17 bidding update changed how budget-limited campaigns bid, targets were realigned the same week; ROAS dipped during relearning and recovered within the month.
The results (vs. the same period a year earlier)
| Metric | Change |
|---|---|
| Revenue | +33% |
| ROAS | +35% (3.8x → 5.1x) |
| Ad spend | −2% |
| ROAS vs. prior year | Up every month since the transition |
Google Ads platform-reported spend and conversion value, spring through summer 2026 versus the same dates a year earlier. ROAS is conversion value divided by spend.
Why it worked
The transition was treated as the strategy, not an obstacle. Fixing measurement first meant every later decision ran on clean data. Giving each product line its own budgets and targets meant none was funded on another’s economics. And head-to-head tests replaced guesswork, so when Google changed the rules mid-summer the account had a known baseline to realign against.
Beating the prior year on return every month, through an agency transition and a bidding overhaul, is what a controlled transition looks like.
Worried about losing momentum when switching agencies?
A transition doesn’t have to cost you revenue. Get a transition strategy that keeps the account learning from day one.
