The vast majority of affiliate programs are managed by a third party “network” such as ShareASale, Linkshare, Google Affiliate Network (formerly Performics) or Commission Junction. These networks will get you registered as an affiliate and then let you apply to individual programs. On the network site, you will have access to tools to add banners and links to your site with your tracking id. The network will also offer real time reporting and handle payments and tax forms. That way, if you earn commissions from 15 different vendors in a month, you won’t get 15 small checks. Instead, the network will consolidate all of your commissions into one payment. This system makes it much easier to track your income and adds an added layer of protection because you are paid out of an escrow account at the time of a sale so that the merchant cannot run out of money before you are paid.