The more I play this the more I have noticed that the fan system is... basically harmful to your business. Fans are bad. That's a problem.
There's lots of things that could be done to fix them, and they've all been suggested. For the current state of the game, with no changes to fans at all, one thing that would help mitigate their harm (and lower the amount of micro-managing you have to do, which is a big problem) is allow *fan first* sorting. One of the problems right now is fans are basically non-customers. You have 130 customers show up, but 120 are fans. That's just 10 customers to go around between the girls who no fans showed up for. If you're doing the fast play method of select any, sort by profit, a lot of times those generic customers will wind up being more profitable than some worker's fans (say, Felicia has 5 fans show up today but they all want handjobs, so you wind up with her giving oral to a different customer). This can lead to your generic customers getting all used up by the time you reach your bottom workers, leaving them with no available customers.
Currently the only way to solve this is to micro-manage your staff, going through your bottom workers first and having them take clients, but when you profit-sort, for some reason it takes whoever is most profitable for your top available (auto-selected) worker and doesn't change even when you change your selected worker. This means you won't be getting the most profit on your bottom girls, but also means that many of *their* fans will actually be buried by generics who are more profitable for the top worker, but less profitable for your bottom worker. Having a fans-first sorting method (or, more likely, a button that applies in addition to the sort) would help fix this one particular problem with the current iteration of fans, since it would mean that generic girls will only go to girls who don't have a fan available, that way they don't wind up getting used up early on. Doesn't fix any of the fundamental issues with the current fan system, but does lower the amount of micro-management needed.
I may make a longer post later about what I see as fundamental game design flaws that lead to this game having just... way too much micro-management and compare it to other brothel games. I really like how active the mod scene for this game is, and it has a solid interface/UI, and a number of good ideas, but as it stands the level of micro-management this game requires is just way too much, and it causes compounding problems with other aspects of the game.