Clickbank is an affiliate network that makes it very easy for you to find affiliate products to promote and get paid a commission. Once you sign up, there are thousands of products that you can browse and they assign you a special tracking URL for any product you would like to promote. When you get someone to buy the product through your link, you get a certain percentage of the sale, usually between 50% and 75%. You can use your imagination with how to promote your links, but many people put them in blogs and websites that already have traffic. It's free to join Clickbank, so you might as well sign up and look around if you are interested in making some extra money.