I'm saying people might be willing/want to pay for nudes if they feel like they have a relationship with the model.

Parasocial relationships are the one-sided sorts of relationships where people get emotionally connected to celebrities, athletes, characters in books and on TV, etc. I can detect it in myself with podcasters, especially. Once I listened to all 200 hours of Mike Duncan's History of Rome podcast, I felt like I "knew" him, even though I only started listening after it was all done, so not only was I just a blip on the download chart, but even then, the personal stuff he shared was years out of date.

So I could see how someone might justify to themselves that they're "helping out a friend" by paying for nudes, even if they could just as easily go find others for free.