It doesn't need to be sustainable as one author or one book. These aren't
real authors. Its people using AI to make a quick buck. By the time the fraud is found out, they've already made a profit.
They make up an authors name. Publish a bunch of books on a subject. Publish a bunch of fake reviews. Dominate the search results for a specific popular search. They get people to buy their book.
Its not even book specific, its been happening with actual products all over amazon for years. People make up a company, sell cheap garbage, and make a profit. But with books, they can now make the cheap garbage look slightly convincing. And the cheap garbage is so cheap to produce in mass amounts that nobody can really sort through and easily figure out "which of these 10k books published today are real and which are made up by ai".
It takes time and money to produce cheap products at a factory. But once these scammers have the AI generation setup, they can just publish books on loop until someone ends up buying one. They might get found out eventually, and they will have to pretend to be a different author, and they just repeat the process.