Beer entrepreneurs: How do you test if your beer will work? (xpost TheBrewery)

Hi!

I've always been fascinated with homebrewing, the arts and the crafts of it, and the enthusiasm within the community. Always a lovely thing to see. However, there's one thing I've found interesting, without any concrete information to be found: How to test the beer and the market.

How do you and/or your brewery test the beer, to see if it will sell? Do you validate your beer?

Do you go through facebook/twitter and ask? Do you just brew it and hops for the best? Do you have a contact channel for people to suggest new brew?