How many affiliate links do you use per page ? I have 2 sites in same niche for a while now EMD both but one rank well and other doesn't. One rank well have less than 5 affiliate links in each page and other have around 10-12 affiliate links.
Looking at this from SEO point of view. We all know Google no longer like pure affiliate web sites they even had a crack down on affiliate blogs on their free blog platform blogger.com So How they would write off you from SERP as an pure affiliate site ?