My friend on social refuses to see how this is a pyramid scheme
Or by her participating that she is knowingly involving herself in a scam. Which, yeah, it's just books - but it's pretty obviously a pyramid.
No shame if you don't see how it's a scam, the cozy blanket and glass of wine are meant to throw you, and they chose 36 because it's a confusing enough number where you don't think too much about how it grows.
She gives one book to her upline. She then sends out post to 36 more people to give her 36 books. Each one of them then needs to find 36 people each, which is now 1296 people in that level if they each want 36 books. Thus the exponential pyramid. Of course there is zero way each of them will find that many people, let alone the levels below that. It's a scam that benefits those higher up, and the ones lower will likely not receive anything.
Of course she sees nothing wrong with that. She said "Sometimes I get books, sometimes I don't, that's just part of the game". Which... it's not a game when it's real money being passed around.
On top of that, whenever we see a pyramid scheme we should be stamping it out - hard. Folks, please spot the signs and point them out. Don't be afraid to comment on posts calling them out as scams.
Edit: To be clear the idea of a growing book exchange isn't a bad one, as explained in the comments though the way to make it not a scam is to make it 1:1. You either send a book and receive a book, or if they like the 36 number, you change it to "I'll send a book to whoever sends me a book!". Then it's a true book exchange.
There was a bookstore in my town growing up that allowed romance novel readers to do a book swap. I'm not sure why since it didn't make them any money.
To get people in the door or talking about the store. Free advertising from a group of readers who are more likely to buy the next and the next and the next in a series of books. Even if you're making one sale instead of two, it's still a sale. And you're more likely to make more than one sale if they buy more than one book (which is likely).
Possibly, but it wasn't a big town and it wasn't a big bookstore. I don't know if that would have worked as a profit-maker long-term, but they were around for at least a couple of decades if not longer, so what do I know?