I have had this theory for a long time that it's easier to get away with blackhat SEO if you have a website that doesn't sell anything. The reason is that most websites that spam with backlinks are doing it to earn some quick bucks. Google obviously hates this since it decreases the quality on search results and take away profit from Adwords. What's your experience? Is it easier to rank an educational site for example than an affiliate site or webshop?