Hiding content on a webpage or hiding affiliate tracking code in links. Hiding content on a webpage is bad as it is against the guidelines of the mainstream search engines such as Google. Hiding affiliate tracking in a link is an acceptable and widely used practice. If you'd like more information, I wrote an article on why and how I cloak affiliate links.
Once you've protected your prospecting pool, maximize your affiliate program by working with the best and leaving the rest. As the old 80/20 adage implies, most of your revenue will come from a very small percentage of your affiliates. Because it can be time-consuming to manage a larger affiliate network, consider selecting only a few companies initially, and interview them before signing them on. Affiliates are an extension of your sales force and represent your online brand, so choose partners carefully.