How Many Conversions Automated Bidding Actually Needs
Automated bidding is a learning system, and it needs a minimum amount of recent conversion data to work well.
What it means
Target-based automated bidding (like a target cost-per-result or target return-on-spend) needs enough recent conversions to learn from. Google's own published minimum for search campaigns is at least 15 conversions in the past 30 days — other formats vary. The commonly repeated "you need 30 to 50 conversions" figure is a practitioner rule of thumb, not the platform's actual published minimum, though more data does generally mean more stable results.
Why it matters
If an account is well below the minimum, a target-based strategy often struggles to optimize and can behave erratically. The usual fix is to start with a simpler "maximize" strategy (which doesn't require a fixed target) until enough conversion volume has built up, then move to a target-based strategy once there's a track record to learn from.
ask datanephew
My automated bidding seems inconsistent — could it just not have enough data?
Ask datanephew how many conversions your account has recorded in the past 30 days. If it's well under the platform's minimum for your bidding strategy, that's a likely explanation.
Should I switch to a target-based bidding strategy yet?
Ask datanephew to check your recent conversion volume first. Below the minimum, a simpler strategy without a fixed target usually performs more predictably while you build up data.