No arrangement lasts forever. They all end. Some sooner than others.
I'd say maybe 30% of my 1st time BCD's don't repeat or may only repeat once or twice more. Almost all of those who don't return are BnB (Bang and Bail) SB's, meaning they declined any non-BCD activities like dinners, shopping, wine tasting, or other out-of-the-house experiences. In other words, they are only there for the cash.
Why? Hard to really know since they generally end the arrangement by ghosting. But I can speculate:
1. Maybe they just didn't like sex with me (old, fat, and I sometimes take a while to finish). Maybe she just thinks I'm too much work. (No matter how much you enjoy eating pussy, let's keep those egos in line, Gents.)
2. They may have found a guy with a much bigger... like maybe 8-10-inch... wallet. Why fuck me for $400 when she can fuck some other guy for $800+?
3. They may have a personal crisis of conscience and conclude P4P is just not for them.
4. Perhaps they get a decent job in their chosen field and no longer "need" the cash.
5. Perhaps they get back with an old, or start with a new, BF or SO.
6. Maybe she got arrested for something (like soliciting).
7. Maybe she got diagnosed with something (like pregnancy!).
For me, I'll be happy that I got to bang a hot chick for a reasonable allowance and I can look to my schedule to see when the next SB in my rotation is due. Honestly, the most difficult part of scheduling is ensuring that I DON'T schedule SB's for back-to-back sessions. I'm too old and out of shape to bang every day... (sigh.).
Life is good
The Cat