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.
If you get a book back, it's not a scam because it's not designed for you to profit, either monetarily or materially. It's obviously misleading saying you'll get "up to" 36 books back, but that's not guaranteed and shouldn't be expected. If someone joined such an exchange (and it was trustworthy), they should think of it as a random book swap and expect to get a surprise book back in exchange for theirs. Anything extra is simply a bonus.
1 for 1: no one gets rich, and no one gets scammed, in theory...
Again, it's unrealistic to expect 36 good books be sent to you, but I guarantee some people will send along more than 1 book, which I assume accounts for the "bonus" ones...
As described, for you to get two books, someone else got zero. For you to get three books, two people got zero.
The median person gets zero books. A few lucky people get 2-36 books.
Edit:
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.
If sounds like the book goes to your upline, and you only get as many books as you recruit people.