Cost Per Acquisition (CPA) is calculated as:
ad campaign cost / [number of impressions x CTR x CR]
: an advertiser pays a CPM of $10. For 20,000 impressions the advertiser has 5 percent click-through rate (CTR) to the landing (destination page). 30 percent of those 5 percent convert to paying customers(CR). The calculation is:
($10.00 * 20,000 Impressions / 1000) / (20,000 * 0.05 * 0.30) = $0.67
That is, the cost per acquisition is $0.67.
PPL as "Pay Per Lead"
Online and Offline advertising payment model in which fees are charged based solely on the delivery of qualified leads. In a pay per lead agreement, the advertiser only pays for leads delivered under the terms of the agreement. No payment is made for leads that don't meet the agreed upon criteria.