Client owns the account
History is the real asset.
Because the account, the audiences and two years of conversion history belonged to them.
The most valuable asset in a paid advertising programme is not the creative, it is the account history — conversions, audiences and learning that accumulate over months and that platforms use to optimise. An agency running campaigns inside its own account keeps all of it, which turns leaving into starting again and is precisely the leverage that structure creates.
Measurement is the other thing routinely skipped. Spending without reliable conversion tracking means reporting on clicks and impressions, which always look fine. Fixing tracking first occasionally reveals that a predecessor's reported success was counting page views, and that conversation is uncomfortable and necessary.
And no agency should guarantee outcomes. Performance depends on an offer, a price, a website and competitors, plus platform algorithms that change without notice. Anyone promising a lead volume is either inexperienced or pricing the promise into the fee.
History is the real asset.
Otherwise everyone is guessing.
Too much sits outside our control.
Free, including a recommendation to change nothing if that is right.