Quora isn't just for entrepreneurs... E.g. http://www.quora.com/Charlie-Sheen-Meltdown-February-March-2...
Who does Sprouter have using it?
Just looking on the http://sprouter.com/answers homepage, here's a taste...
Dan Martell - Flowtown, Aaron Patzer - Mint, Micah Baldwin - Graphic.ly, Mark Suster - GRP Partners