Yesterday was my third art market of the year. Throughout these three shows I have kept a reciept book, a.) to look legit b.) to keep my accounts in order and c.) to take notes on my buyers.
I urge all sellers to do this. Not only will it inform you about who likes your stuff, but it is really funny to go back and read later. For (totally doctored) example:
Once you know your audience, ask "Is this who I am making things for?" If yes work this knowledge to better your product and reach the people who will love it. If that answer was no, enjoy a nice surprise and consider multiple directions.