For small nonprofits like us the issue is money and skills. We don't know how to set up something on our website, and don't have the money to pay someone else to do so. I have lots of ideas about how it'd be great to use the social web to further our work, but, given few resources and other work we HAVE to get done to exist . . .  hopefully at some point we'll find an organization or person who can help us get set up free or inexpensively.