is it worth using social networks for fundraising?

Lots of people are talking about using sites such as MySpace, YouTube and Facebook as a way for charities and campaigning organisations to link up with supporters. This may be a new channel for networking with existing supporters, or a way of recruiting new supporters, through recommendations and online connections.
Such social networks are free to the user, and can be appealing as a way of reaching a new demographic mix. As with online worlds such as Second Life the yoof that supposedly lurk in such sites are the donors of tomorrow and are like gold dust.
But what does it cost and is it a good use of your time? Even if you know what you're doing you can spend hours keeping your profile up to date, adding news and chasing down new contacts.
Justin Perkins at Care2 has done some serious work on whether you can calculate the return on investment in time and effort. for many small groups it will best to find a volunteer to explore this option, but for larger charities, who are already investing heavily in online fundrasing tactics, this is a serious question, which weighs the short term costs of the time spaent against the medium and long term risks of NOT doing it.
Find out more and try the calculator at http://www.frogloop.com/social-network-calculator