I'm going to guess that its because there's a few "names" in the industry who do actually get a real share of the profits, probably because they have a lawyer (

I'm going to guess that its because there's a few "names" in the industry who do actually get a real share of the profits, probably because they have a lawyer (or more likely, a legal staff) to make sure that all the details are negotiated with their interests in mind. Like anything else, you need a little luck and a lot of work to get to that point.