I think it depends on how you go about it. If you just make it available and from the outset make it known that's what you're doing, then I think it's fair gam

I think it depends on how you go about it. If you just make it available and from the outset make it known that's what you're doing, then I think it's fair game. If, on the other hand, you spent time convincing people to use it and then just abandon it, I think that's kind of a jerk move. I see this happen a lot with freelancers using open source as a means to drum up clients.