An affiliate program network is a website-based service that acts as an intermediary between affiliates and merchants. Whilst most require their publishers (affiliates) to operate their own website, they are also interested in other promotional methods you may employ such as blogging, social media and ppc.

For the merchant, the use of a popular network allows a much wider, targeted reach to those webmasters that are interested in promoting their programs in return for a commission on actual sales, and occasionally on lead generation.

For publishers, affiliate program networks offer a very user friendly interface through which they can select and apply to numerous affiliate programs that are a match for their websites content and theme.

most merchants will review each application for suitability. By selecting only those programs that are a good match, not only are publishers able to choose those programs most likely to illicit a response from their site visitors, but they add contextual value to surfer's perception of the product or service being promoted.

Most affiliate programs found via affiliate program networks offer the publisher commissions or earnings on a CPA model. CPA or Cost Per Action can sometimes refer to a set fee per action performed by a site visitor. more often, however, it is in fact a revenue-share model wherein a percentage of revenue is passed onto the affiliate.

Merchants benefit from a number of tools that aid in the management of an affiliate program in addition to the increased exposure. These can include sophisticated tracking and reporting, payment processing and escrow.

A further advantage for publishers and affiliates is the payment of all commissions to one account with the affiliate program network. This allows websites to vary the products or services offered without having to wait for a minimum level of earnings at each merchant.

There are also CPA networks. These are not to be confused with the networks described above. These are what might be called 'super-affiiates'. Whilst still offering similar deals, they are actually passing on some of the higher commissions they command through higher volume to their 2nd-tier affiliates. These will ordinarily control the content and advertisement delivery to a members website.

The top-performing Affiliate Program Networks can be discovered at this Human-edited Marketing Online Directory.