Bad publicity is still publicity. Whenever there are scandals or rumors or any hot news about a celebrity, it helps them gain more visibility in their target audience. This is a big reason why in my country, whenever they are trying to introduce a new artist or when they are trying to promote a new movie, they publish articles (most of the times outrageously scandalous) about the actors just to gain attention. And unfailingly, the public falls for this trap. The next thing I know the movie earned lots of monies. And it doesn't matter if the movie is good or bad. The publicity just has to be highly visible. Bad publicity takes care of that.