This sort of thing was a big deal in the early days of the online gaming industry, when most games were just text (MUDs) and very similar. It started all sorts of "MUD Wars" between games, with people stealing members, accusing of stealing members, etc. And this was when the games were hosted mostly on University computers and running for free (early days of the internet, mid 90s). So this was all about pride and bragging rights. Nobody's paycheck was affected even.
Games and their players are just like models and their members: you can't really steal a member or have one stolen. Every model is offering something different - her looks, her personality, the games or ways she entertains, etc. Every member is also looking for something different. The ultimate truth is that given enough time, members will find the models that appeal to them the most, and whether they find them by accident or with a nudge, the thing that is going to make them "change" is simply a better fit.
So just as I had to learn as a game developer, you can't take it personally. If someone prefers a different game, model, brand of cola, whatever, you can't really do anything about it. Getting upset that the customer found someone more suited to them is just part of the natural flow of commerce.