I think this should be a very enlightening question for many providers. The ladies that have answered have already shown a "head" for the business side of things. Many ladies that are lurking, I'm sure, have not. They either only look at their income, not their expenses. Or they have the "strippers mentality" of taking as much as they can as fast as they can.
I spend a LOT of time working with my distributors, who are small business owners. The majority of that time is spent working on "Business 101". Many people get into a business for lots of reasons, usually because they know the product or the market. But few know how to run their operations profitably. They have no real clue of what their cost structure is, so they have no true idea of how much (or little) to sell their product for.
Over the years I have seen the same thing from the vast majority of girls who get involved with this. On one hand many (certainly not ALL) of these girls look at the money and realize that for only "working" 2 or 3 hours (only taking into account the date time) they can make more than they would make working in a normal business environment for 40+ hours. And that's still true, especially if the girl is looking at working in an entry-level retail or office setting.
But one of the things I've told many, many, MANY girls (and few listen) is that this IS a business for them. They need to run it like one. They need to invest back into the business. Just like any professional needs to update their skill set, they need to think of things like taking care of themselves. Spending a little money on their outfits. Making sure they have enough cash or a credit card to get a room if need be. They need to think of things like marketing themselves, handling the admin details, like making sure they've got enough minutes on their phone to actually deal with the screening and setting up appointments. Taking time to educate themselves on the hobby, hobbyiests and what's safe and not safe to do.
But, just like many of the small business owners I see, they just don't want to deal with the "business" end of the equation. They think that just because they're hot, or good at what they do, they'll always be OK. It's rarely the case. If you don't take care of "back office" operations in ANY business, you will not be in business. I know one girl in particular that basically does nothing for an entire week. Never works out, never updates pics, never gets new outfits or toys. But then when she needs money, she posts an ad and gets pissed when the phone doesn't start ringing right away. So to entice guys, she lowers her rates or offers discounts or "promotions". This is the classic case of a reactive business strategy, and it's always doomed to fail. This individual constantly wonders why she's broke. Hmmm, I wonder....
Like Q, I have an appreciation for the efforts that girls DO put on "behind the scene". I would never claim to have a full understanding of it (although I think it'd make a GREAT business case study for a business student! ). But I can usually tell the girls that do have a grasp on it (or are grasping it...it's a process). It shows off in their longevity, the fact they can maintain their rates higher and that they have a more loyal clientele, which actually makes things easier by lowering the amount of screening and marketing they have to do.