However, we can likely attribute this to a clear case of demographic sampling bias, probably based in part on the age cohort for such sites skewing younger than the broader Internet audience, and thus being more likely (if the demographic breakdowns in traditional, offline polls are to be believed) to favor Obama over McCain. For example, looking at and "friends," the advantage noted for Obama in the site traffic numbers widens considerably, with about four times as many users "friending" Obama as McCain.

Plotting this trend over time at  and we clearly see Obama's long-term domination of this youth-oriented environment.

A particularly vivid example of the possible sampling biases in Web 2.0 type metrics is provided by techPresident's chart of candidates' supporters who are using the online social networking portal . Here, not only do Obama supporters outnumber McCain supporters to an even greater degree than we saw with Facebook and MySpace, but even more notably, the supporters of third-party candidate Bob Barr actually eclipse McCain supporters and rank a close second to Obama supporters. Clearly, this particular Web 2.0 metric is measuring something quite different than what we find in traditional polling results.

Clearly unrepresentative anomalies like this one aside, the techPresident site is a particularly rich source of Web 2.0 metrics of candidate popularity. Its partnership with online video analytics firm TubeMogul, for instance, gives techPresident the ability to show detailed dynamic visualizations of total video views for each candidate on , as in the following pair of charts:

The day-by-day data here is somewhat "noisier" than some of the other metrics we have looked at, with wide swings between the two candidates' video viewership numbers (compare it for instance to Google's daily traffic numbers for the candidates' Web sites). Intuitively, YouTube viewership seems more responsive to day-to-day events (in both traditional and online media), resulting in the greater variability. Still, the overall trend is clear, as the cumulative viewership trend lines demonstrate, with Obama building up a long-term advantage that closely mirrors his 4-to-1 advantage in the social networking sites.