The two main parties involved in the affiliate relationship are the merchant (sometimes also called “advertiser”), and the affiliate (sometimes called “publisher”). There are different ways to run, manage and promote affiliate programs, which involve more parties in the relationship, but the two main participants (without which the existence of the very marketing channel would’ve not been possible) are: (a) the party that has the product (or service), and (b) the party that knows how to sell it.
There are two ways to approach affiliate marketing: You can offer an affiliate program to others or you can sign up to be another business's affiliate. As the business driving an affiliate program, you'll pay your affiliates a commission fee for every lead or sale they drive to your website. Your main goal should be to find affiliates who'll reach untapped markets. For example, a company with an e-zine may make a good affiliate because its subscribers are hungry for resources. So introducing your offer through a "trusted" company can grab the attention of prospects you might not have otherwise reached.