An advertiser is launching a new Demand Gen campaign using target CPA bidding with a goal of $15 per conversion. To allow for sufficient conversion volume for AI optimization and avoid an underperforming, budget-constrained campaign, what's the minimum daily budget they should set?

The daily budget should be $150 — roughly ten times the target CPA. The guidance exists because Smart Bidding needs enough conversions to learn from: a budget that only funds one or two conversions a day leaves the model with too little signal, learning drags on, and the campaign is judged on noise rather than performance. At ten times the target, the campaign can produce around ten conversions a day, which is generally enough for the system to find patterns and stabilise. Two related habits follow from the same logic. Give the campaign a couple of weeks before drawing conclusions, since the learning period needs completed conversions rather than elapsed time, and avoid frequent budget or target changes during it, because each significant change restarts the learning process.