I think the fact that someone took the time to create a thread about her on a BB board, about the amount of money she makes per appearance, tells you all you need to know - in regards to clubs paying for her to appear. She draws attention....
A club may pay her 10k to appear, but they make far more money from the ( stalker guys and wannabee girls) that show up to "party" with her. Plus, they get a bunch of free press, which makes them look "exclusive". I worked in the nightlife scene for years, this is pretty common, and she is pretty "cheap" considering what some celebs command.
A little ot, but I know for a fact Paplebon just got 50k to do a book signing , here in Boston.