Jeff Pulver, and by extension, Chris Brogan, have been enjoying some robust commentary on Jeff's recent BusinessWeek article and post about switching his business social networking to Facebook. Comments - some rather direct - have been made back and forth about Facebook and LinkedIn and who's on what. Here's a different perspective.
Christopher Alexander, in his seminal work, The Timeless Way of Building, makes the point that how we use a space defines the space. Put a bunch of benches in rows in a long rectangular room with a pulpit up front and you have a church. Put a bench on a lawn in the middle of some greenery and you have a park. You'll get variations, of course, but the function defines the space.
So it goes with social networks, and how you use them. Facebook is a social space, used to develop and grow community, but the odds of you getting data out of it are very, very small. They rigidly enforce the walled garden on data, so for managing contacts and relationships in the sense of a CRM, Facebook wasn't built for that. LinkedIn is both a resume manager and a CRM of sorts. You can push and pull data from LinkedIn with great ease, but its interactive capabilities for things like discussions, polls, and community activities are very poor.
To force LinkedIn to become a community or Facebook to become a CRM would be futile - each has its purpose, and you need both, at least from my perspective as an online marketer. If you have a list of email addresses and incomplete contact information, nothing will help verify and clean that list faster than LinkedIn - but if you want to create forums for the people on that list to have a conversation, Facebook is the place. If you want to market music or media online, MySpace for all its flaws is still the best place to be, as I'm discovering marketing my Student Loan Radio music podcast.
And if you, like me, are tasked with doing it all for a company or organization, you'd better have a flag planted in the soil at each place, and have appropriate media deliverables for each.