The SAG Foundation had a panel on the business of comedy a couple of weeks ago.
On the panelist was Oscar Nuñez (The Office), Bruce Smith (Omnipop Talent Group), David Goldman (Comedy Time Network), stand-up comic/casting director Lesley Wolff and casting associate/stand-up comic Chris Gehrt.
They talked about why improv training is important, the reality of open mic nights and the importance of writing.
Incidentally, I took a class from Lesley Wolff once and it was such a great experience. It was a 5-week course and where the final night, you did a 5 minute stand-up routine at the Improv. If you get a chance, I highly recommend it!