Amazon has spent years perfecting the art of online selling and you’ll learn a lot about online marketing by observing how they do it. They constantly test different ways of promoting products and have evolved their site quite a lot over the years. See what widgets they use to promote related products, watch how they use reader reviews, and see the way that they describe products.
Unfortunately, the 2Checkout dashboard is a bit limited in scope, making it difficult to get any metrics on conversion rates or even sorting by commission payouts. The workaround is to go to the Avangate store, which does list their best-selling products, and then search for these on the affiliate dashboard. That being said, 2Checkout does offer products from more than 4,000 different vendors, making it the leading affiliate network for software and digital products.