domaingamer - 12:08 am on Mar 2, 2010 (gmt 0)
I understand what you're saying regarding the fact that thin affiliate sites can get banned and I wouldn't doubt it. I'm only giving my specific example across 30+ websites. Many of my other sites that weren't selling links were also thin affiliate sites and didn't get banned. I assumed that the thin affiliate sites made it through because they weren't selling links. Now maybe that's coincidence, but I surely wouldn't be ruling out a link selling penalty occurring. Just like I won't rule out thin aff sites getting penalized - but I don't think I've experienced that based on my set of circumstances.
As a side note, I consider MFA sites thin sites, but would be surprised if they got regularly banned since they are very much helping Google and it's really not in Google's best interest to ban them. Unless maybe you get a bit too high and mighty in your rankings and incur the wrath of some brick and mortar companies that also just happen to be large AdWords spenders.