Pay per lead (PPL) is a form of cost per acquisition, with the "acquisition" in this case being the delivery of a lead. Online and Offline advertising payment model in which fees are charged based solely on the delivery of 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.

Leads may be delivered by phone under the pay per call model. Conversely, leads may be delivered electronically, such as by email, SMS or a ping/post of the data directly to a database. The information delivered may consist of as little as an email address, or it may involve a detailed profile including multiple contact points and the answers to qualification questions.

There are numerous risks associated with any Pay Per Lead campaign, including the potential for fraudulent activity by incentivized marketing partners. Some fraudulent leads are easy to spot. Nonetheless, it is advisable to make a regular audit of the results.