tedster - 6:07 pm on Apr 19, 2013 (gmt 0)
I think ColourOfSpring has the right idea - Google wouldn't care how you "pay for" links. If they're not naturally given, then they could be suspect. However, many sites do acquire links through various types of favors and still thrive, because after all it's not easy to detect the many possible scenarios. Things also get pretty fuzzy, trying to find a definite line here.