I think Karinne Steffans may have described it best when she said that everything she ever did (as outlined in her memoir Confessions of a Video Vixen) was a form of prostitution; she was having sex for money or gifts. Perhaps not directly, with $50 on the nightstand, but things were being given to her and bought for her, and her lavish lifestyle was being supported on the condition that she continued to make herself sexually available to rich and powerful men.
I kind of think as Trophy Wives in the same way. I wouldn't out and call them prostitutes, but they'll often marry a wealthy man, even if they aren't attracted to him or in love with him, because they know that they'll be able to use their sex appeal and sexual ability to support a lifestyle they wouldn't otherwise be able to afford. The difference between them and your regular streetwalker is better outfits, a much more comfortable living situation, and a marriage license lol
Of course that's just how I see it; I have a friend who's with a guy simply because he's well off, and the whole thing is just disgusting to me. She's always telling us how she's not into him, she's not attracted to him, she loves that he travels so much for work because then she can be with other men. When she has sex with him, she confesses to drifting off about something else to get it over with, but stays with him because the gifts and money she's receiving are like nothing she'll get from any of the guys she's usually dating. And she fully intends to marry him if he proposes, despite the fact that she's not into him at all and thinks she could never ever love him. Disgusting.