ponyboy96 - 2:15 pm on Aug 13, 2010 (gmt 0)
I once saw a link on a PR 8 page by Doc Searls do absolutely nothing to rankings for the target site. It did, however, bring in a lot of direct traffic. It was experiences like this that taught me to dig a lot deeper into Google's ranking algorithm.
It may provide you some value, but I usually tell my clients it can take 3-6 months to see the full benefit. On another note, if that link is providing you traffic and some conversions, then it's a big win.