Absolutely.....of course it depends on what promotion you are after. For generating gig attendance or customizing page layout, MySpace is a superior instrument but Face Book provides a far deeper level of networking for the musician to musician and the musician to fan. It is easier to navigate and provides a massive amount of filtering and exposure tools.
A 'profile' page setup can be done by each individual band member then each indivdual band member can become an administrator to the full band page. Each band member has friends that can be simply recommended to the band page or application page to be fans. Then with application tools like "ilike" or my recommendation "My Band" through reverb nation all of these accounts including Myspace...youtube....bebo etc can be linked through the My band or Ilike application and administered that way.
If you want....you can email me to discuss a bit but anyway yes it is an invaluable tool IMHO and as the network grows so does the exposure and promotion.....She told 2 friends and so on, and so on, and so on, Facebook is like the ultimate networking pyramid scheme.