Cost per action (CPA) is a pricing model for line items. The pricing model is based on actions users might take as a result of seeing an ad creative. If the desired action takes place within a specific time frame, sometimes called a "look-back window", the action is attributed to seeing the ad creatives. A successfully completed action within the look-back window is also called a conversion.
Costs for CPA line items tend to be higher when compared to CPM or CPC line items.
When you set up a CPA line item, you associate activities with the line item.
Conversion counting with CPA line items
To attribute a conversion to a CPA line item, Ad Manager follows the usual attribution process, checking whether a click or an impression falls within the appropriate look-back window. However, when an activity is associated with one or more CPA line items, Ad Manager changes the conversion attribution process to give preference to those line items. The attribution hierarchy is as follows:
- Click of an associated CPA line item
- Impression of an associated CPA line item
- Click-through conversion
- View-through conversion
In other words, Ad Manager looks first for a CPA-associated click or impression, then a click-through conversion, then a view-through conversion. If there is more than one eligible CPA-associated click or impression, Ad Manager gives preference to the most recent click. If There are only CPA-associated impressions, Ad Manager gives preference to the most recent impression. Among CPA clicks and impressions, relative price is not a factor in conversion attribution.
Set up a CPA line item
To set up a line item:
- Follow steps to add a line item. Choose an advertiser that uses conversion tracking and has activities.
- In the Settings, set the Rate to CPA.
In the Activities text box, choose an activity.
- Enter a Click-through CPA, which is the cost per action associated with a user click.
- (Optional) Click Enter view-through CPA to add a cost per action associated with a user impression. If you don't add a view-through CPA, view-through conversions can still be counted when users view this line item, then complete an action; however, no additional cost will be added to the line item when that happens.
Conversion limits are no longer supported. To end delivery, pause or archive the line item.
- (Optional) Repeat steps 3 through 5 to add more activities to the line item.
Save the line item.
Line item types not supported by CPA pricing
Only goal-based and percentage-based delivery priority options are supported by the CPA pricing model. This means the following line items types are not supported by CPA:
- Price priority
- Dynamic allocation line items
- Ad Exchange
Report on a CPA line item
Use the CPA revenue metric under Conversions in Ad Manager reporting to evaluate revenue activity on CPA line items. You may want to include the "Line item" dimension to see a breakdown of revenue across CPA line items.