Something I've noticed in Google Ads audits.
The bigger the account, the more likely they have bid limits on smart bidding.
€500K/month accounts? Almost always capped.
€10K/month accounts? Almost never.
The conventional wisdom
"Bid limits defeat smart bidding."
"Let the algorithm optimize."
"Some clicks cost more because they're more valuable."
And I get it. Logically, that makes sense.
But here's what I'm seeing
Large accounts with experienced media buyers set bid limits anyway.
Not because they don't trust the algorithm.
Because they've seen what happens when you don't.
- Single clicks at €80-100
- Budget eaten by a handful of auctions
- Volatility that makes forecasting impossible
I don't have a definitive answer
What I do have is a test I want to run:
Same campaign structure. Same budget. One with bid limit X. One with bid limit Y.
Let the data decide.
The question for you
Do you use bid limits on smart bidding?
If yes - what's your logic?
If no - have you tested it?
I'm genuinely curious. The more accounts I audit, the more I see experienced buyers doing things that "shouldn't work" according to best practices.
Sometimes the practitioners know something the playbooks don't.