I didn't find the authors argument to be particularly compelling. Sure facebook may be able to motivate people to do small things like make a donation but he offers no evidence to counter Gladwell's assertion that really revolutionary change won't be driven by social media. I'm not saying that tweeting and facebook won't be involved in revolutionary change, just that they probably won't drive it. Just look at the teaparty as an example ... one of the biggest social movements of our generation and they are certainly not social media driven