I have not yet read Sasha Issenberg's book (it's on my holiday wish list!), although I imagine there are still several books to be written about the use of social networking software by the presidential campaigns this year. This subject came up quite a bit at last week's post-election panel here at the University of Denver. Sunshine Hillygus explained how the Obama campaign had hundreds of different search algorithms in their on-line advertising that combed through your computer's browsing history and geographic information to assess what kind of message might resonate with you, and then selected one of hundreds of pop-up messages deemed most likely to affect your vote. In general, while both parties are making advances in this area, right now it seems like the Obama folks are simply more technologically advanced (and borrowing heavily from the social sciences), although whether this actually explains their recent victories remains to be proven.
Another advance that amused me was the Obama campaign's use of social pressure in its e-mail contacts. Here's a message I received about a week before the election, when mail-in voting was available in Colorado:
Hey, anything to break through the clutter.