If the main purpose of the ad is to generate sales, cost per order is the preferred metric.
The CPO model is superior to other concepts that don't take into account the actual value of an online campaign.
[5][6][7] This is because a high volume of targeted traffic, number of impressions, and click-through rate do not necessarily lead to sales, even if these metrics are important from a digital marketing perspective.
[12] Typically here, CPO is closely tied to the commission paid by the product seller to place ads with affiliates.
The precise form of this cost depends on the industry and is complicated by product returns and multiple sales channels.