CauseWired, subtitled "Plugging in, getting involved, changing the world", is a book about online fundraising by Tom Watson. Here's a two minute review, not because I think you don't want to spend more than two minutes reading it, but because I don't want to spend more than two minutes writing it.
(If the name is familiar Tom Watson is the name of a blogging UK MP, but the book is by another Tom Watson.)
Lots of stories and examples. Well researched. Nothing startling in there if you've been following the stories about fundraising organisations through blogs. Lots of people, say, signing up to a Cause on Facebook doesn't mean lots of giving. In my opinion the whole thing is too young to draw any conclusions that will stand the test of time.