A couple of weeks ago, I attended the Personal Democracy Forum conference. One of the best sessions was by danah boyd (she doesn't capitalize her name), a researcher currently working for Microsoft. She basically whacked us over the head with the fact thatdespite similar numbers, the people on Facebook aren't the same people on MySpace. And really relevant to gov't use of these sites, those on FB are (or at least are perceived to be) better educated, wealthier, and more "elite'ile MySpace is for others.
The upshot for those of us in gov't? If we focus only on one site, we're missing a whole lotta people. And if that site happens to be Facebook, we may be missing underserved groups entirely.
The challenge, as always, is covering everything with the same, limited resources.
But danah convinced me we have to try to be on both sites. So we'll do our best.