Affiliates use free tools to place links on their sites that lead users to eBay. The most rock-bottom simple option is simply a link to the eBay home page. But Martin-Gill says savvy Affiliates are carefully selecting the links they place. Getting your users to pages likely to be of interest to them is smart strategy. If you write a blog reviewing sound cards, for example, you could have a link on your main page that takes your readers directly to a list of sound cards available on eBay. That's a spot they might find something to buy, whereas directing them to the road bikes category might not result in as much revenue for you.

But you can go far beyond a simple link to the home page or a specific category, Martin-Gill said. Depending on the time you want to commit and the level of programming you want to undertake, you can select from a variety of tools to maximize your effectiveness.