9 Laws of Social Media Marketing

Jim Gilberts comments on the 9 immutable laws of social media marketing are a good read. Very clearly put.
I'd like to add a couple of observations
1. The argument for social media marketing is in the short run not as compelling for some brands - it depends on target markets and brand promise.
2. You have to measure the impact of social media marketing and though perfectly possible it is not easy - unless you plan carefully. What people often complain about Social Media marketing is they can't measure the impact of it. I remember the reaction of Dixons to realising that most of their shoppers in their electrical stores had already researched and done price comparison on line before visting the store... thats a good analogy to how Web 2.0 is now
3. Beware hype - look at 2nd Life - I was never a convert because I just did not see a tide of people using it.