On we see a markedly different pattern. While both candidates have the maximum viewable 500+ friends, note that the McCain campaign has recommendations and has made one (Sarah Palin) while the Obama campaign has none. (Read a of 12 tips for safe social networking.)

Readers might suspect the business focus of LinkedIn is at work here, but in our view the numbers are too low to make that conclusion reasonable. Given these remarkably low totals -- including zero recommendations for Obama -- we suspect campaign editorial decisions may be minimizing the use of this particular network for political expression. This is likely analogous to McCain's near-invisibility in other Web 2.0 systems notably online event systems like Meetup and Eventful.

In general, our research into Web 2.0 type metrics forces us to conclude that, when using the Internet for social-observational purposes as we are doing here, following the law of large numbers seems to be a good way to control sampling bias, whether it results from the demographics of self-selection or conscious decisions on the part of the campaigns about where to focus their efforts.