Last night I was hanging out with some friends and was asked my advice on how to promote an improv show (two in the party are in a group looking to promote their performances). My advice was that I thought the best marketing advice is "try a lot of stuff and keep what works." This is lifted from Good to Great by Jim Collins, a great and insightful book about business.
Then today, I remembered a really great list that Dan Goldstein wrote up, "How to promote your show: 14 things to do." Here is this list. Simple, direct, effective. While it was written in New York five years ago (note the mention of subways), I think everything on this list is right on. Dan is a Assitant Professor of Marketing at the London School of Business and an expert in the field of decision science (he gets name checked by Malcolm Gladwell!). He also is an incredible improv talent, as a performer and director/creator of shows.
(photo "Jerm and Marc's improv flyer" by Marc Majcher, licensed under Creative Commons, some rights reserved)