As I wrote previously (which I now cannot easily find), I do not agree with the conventional wisdom for linking blogs to generate traffic as it assumes the goal of my blogging is to get more readers. I link to those sites I find interesting because those who read my blog may also find the sites interesting. Many of the measures of a site's traffic rely on counting links, so the more people who link to your site, the higher you are ranked.
This is an excellent post about linking, the bias in current metrics and the forces behind links. The core issue, as I see it, is that the blogosphere is not homogeneous, just like the print media is not. It would be like comparing such diverse print media as the NY Times, The American Poetry Journal, Garden Design, JAMA, the monograph Game Theory, Optimal Stopping, Probability and Statistics, Farmers Almanac, and the local shoppers newsletter. Well, you get my point and I'm having too much fun finding print media to illustrate a point that was already made by Zephoria.