Sadly, these things are rarely clear cut. There's no way to answer this question without offending someone. If people respond with comments, they will probably be of more use to you than my answer. Also, I don't have any idea what you mean by a niche market theme. It depends on how unique your show is. I can honestly say that if I know someone did a show based on The Canterbury Tales, I then would not do a show based on The Canterbury Tales, so that should say how i feel about it whens someone does something because they saw you do it, and I've been on both ends of that. But if they did one based on rockabilly or horror movies or fetish, I probably wouldn't think of that as being unique, all else being the same. I was just talking to someone the other day about people who think that because they thought of using a particular piece of music, they think no one else should, even though the creativity originates with the composer of the music, not the person who dances to it. That said, people do become identified with particular songs; I'm happy that so far I haven't seen anyone besides me do a number to International Lover (which doesn't mean no one has or will, just that I don't know). If someone saw me use it and then used it, I wouldn't like them so very much, though whether or not they were unethical is up for debate. But when people come from fields where there is repertory, like ballet or theater, where people do use the same music and same themes, they might not see a problem. So there is no black and white answer. Niche market things can be tough because if a show is based on, say, a particular fairy tale, the origin of the creativity there is from the author of the fairy tale, not the producer. Perhaps if it's something like Alice in Wonderland or the Wizard of Oz, that's less unique than if it's Little Lord Fauntleroy or White Fang. But I wouldn't want to be known for putting a similar show to something already existing; I like to try to make odd things interesting bases for shows, like cheese. I've been doing the Follies Fromage at Coney Island since 2005, and so far I don't think anyone else has been very interested in doing another cheese-based burlesque show. It's too cheesy.