As far as I can tell, his claim to fame is writing a narky email to someone who's paying ~ $40K/year to learn. What unique or interesting thing does he bring to the table? "Being nasty to your customers" doesn't work as well when you're outside of the sheltered workshop that is academia.
He co-founded Red Envelope and ran an activist campaign against the NYT. The combination of high IQ, strong opinions, and borrowed money more or less requires asshole behavior (every minute you fail to convince someone is a minute you're paying interest on. Replace "interest" with "rent," and you can explain New York City.)
Red Envelope Saga All But Over (http://techcrunch.com/2008/04/03/red-envelope-may-be-heading...)
Deadpool: Red Envelope Files For Bankruptcy (http://techcrunch.com/2008/04/19/deadpool-red-envelope-files...)
It's not necessarily Scott Galloway's fault, as he was kicked off the board in 2004 (although he did get back on the board in 2006 after buying up enough stock to push it through) but I'm not sure it passes the 'successful' test.
(The value proposition is actually a bit puzzling given you could lock yourself in a cheap apartment somewhere for ~18 months and try out different business ideas without having to work for the same amount as a years tuition).