tedster - 12:04 am on Oct 29, 2010 (gmt 0)
There's no doubt Google is tough on sites with affiliate links. If it looks like the primary purpose of the page is just to squeeze the visitor into buying something through an affiliate link, it's very unlikely to rank well.
On the other hand, if the site serves some unique purpose as well, and doesn't just use thin content that appears other places around the web - in Google's words, if it adds real value - then the pages can rank. The judgment calls involved appear to come from their human evaluators, not an algorithm.