The document provides an overview of performance marketing and affiliate marketing. It defines affiliate marketing as a marketing channel where outside individuals or companies (affiliates) advertise products or services on a merchant's behalf in exchange for payment. Affiliates get paid through various offer models including revenue sharing, lead generation, and cost-per-action. Affiliate networks track affiliate sales and commissions using pixels. While networks make the process easier, merchants can also track affiliates in-house. The affiliate marketing industry is large and growing, projected to be a $4.1 billion industry in 2014. The document outlines different types of affiliates and considerations for returns and fraud.