Affiliate marketing is a performance-based marketing strategy where affiliates earn commissions for promoting others' products or services through various online platforms. Affiliates receive unique identifiers to track sales, and they can earn commissions typically ranging from 30% to 100% based on the program specifics. Several affiliate programs, such as ClickBank, Payspree, PayDotCom, and others, offer different structures for payouts and tracking sales, making it accessible for those with basic internet marketing knowledge.