Set and adjust your
Consider how much you want to spend on
You have the option to set a cost-per-acquisition (CPA) cap at the ad group level in your search results campaigns. The CPA cap setting specifies the amount you’re willing to spend for a conversion. Keep in mind that the CPA cap you enter will set a bid ceiling for all the keywords in your ad group, even if you have max CPT bids that are higher than your CPA cap. The bid ceiling that will be applied in your ad group will be calculated based on the CPA cap that you set.
Bid ceiling is calculated as: CPA Cap x Conversion Rate
For example, if your CPA cap was $5 and your conversion rate is 65%, then the calculation would be:
$5 x .65 = $3.25
In this instance the max CPT bid that would be applied for all keywords in the ad group would be $3.25. If the max CPT bid was set at $4, the max CPT bid applied would still be $3.25.
If your keyword max CPT bid is lower than the result of the above equation, it’ll be applied instead.
Setting a CPA cap is completely optional and limits impressions and conversions. Consider giving your campaign time to run so you can learn from the results before you set a cap. Note that your CPA cap isn’t guaranteed. Once set, you can adjust your CPA cap at any time.