Advantages of public statements on sites (vs email)

I read something interesting at home and forwarded it to work. On Newsweek's site:
http://www.blog.newsweek.com/blogs/stumper/archive/2008/02/05/the-viral-vote.aspx

The author makes some good points about how tools on social networking sites make for very effective endorsements (in this case, political candidates, but it applies to other areas too).

A relatively "old school" way of endorsing candidates was to send out emails about it. Times have changed, the author says:

"But email is so, like, 2004. ...To compare, I haven't received any email endorsements, but six friends have already invited me to join the "I endorse Barack Obama" and "I'm voting for Obama today" groups on the social-networking site. The gap has a lot to do with the different technologies involved. Email is private: a closed-circuit conversation, often between two people, it provides no context beyond the content of a particular message. Facebook, on the other hand, is largely public: it exposes everything that your entire web of contacts is doing, saying and sharing at any given moment--and invites you to participate.

When I clicked on the message, I was immediately redirected to a page that tracked the activity of the "endorse Barack Obama" group. There were more than 20,000 members and 440,000 endorsements, with links to discussion groups and user profiles; every time a friend joined, a bulletin automatically appeared in a News Feed on my homepage. It was, in effect, a self-perpetuating community. As get-out-the-vote efforts go, it's a whole lot more convincing--and a lot more "Obama"--than a single testimonial sitting in my inbox. Facebook actually reveals how you're participating, as Obama says, in something "bigger than yourself."

My particular point about this is that we've been talking about how there are so many different ways now for reaching people, and some can really spread the message to more people than we realize at first. So, efforts like the above (which sound kind of Web 3.0 to me) are more effective than the older ways of email blasts and mass mailings, even though we still have a need for those methods. Maintaining email lists and mailing lists can be very time consuming, and they can quickly become obsolete, whereas these social networking methods don't have the same limitations.
I thought this was pretty cool!