buckworks - 5:27 pm on Jun 28, 2010 (gmt 0)
how relevant the site is for certain keyword phrases
Up to a point I'd agree with that, but when I go link hunting my biggest focus is the relevance of the PAGE that my link would be on. That could easily have some nuances that are different from the site as a whole.
In my opinion, if you focus on obtaining links from places where the direct human traffic would be well targeted for what you're promoting, such links will send useful signals to the search engines. The strength might vary but they'd be the right signals.