If don't do conventions, or you just don't buy art at conventions, by all means don't worry about responding -- I forgive you! ;)
Have you ever commissioned a badge/sketch from me at a convention?
If you have...
1) Did you feel like you got what you asked for?
2) Did you feel like you got your money's worth?
3) Did my prices seem fair?
4) Did the item exceed your expectations in any way?
5) If there was something you weren't happy with about the item, did you tell me about it?
If you haven't...
1) Is there a particular factor that made you choose not to? Art style? Subject matter? Price? The queue was full before you got to my table? I've never been to the one con you ever go to? (Don't worry about hurting my feelings here ... when it comes to this stuff, I'm quite thick-skinned.)
2) Is there a specific thing or set of things I could do that would make you more likely to in the future?
If you used to but don't any more...
1) Is there a particular reason you stopped? Art quality? Variety? Is it a matter of, "I've got a piece by The Gneech already, time to get something from somebody new..."?
2) What could I do to interest you in new pieces at future shows?
Any and all input welcome and desired! Thanks, everyone. :)