From the article, it sounds like this gaming the system is more common for niche areas like advice and less so with the main fiction list. Besides niches being

From the article, it sounds like this gaming the system is more common for niche areas like advice and less so with the main fiction list. Besides niches being easier to manipulate, the economics are different. An advice author is often trying to use a book as a self-promotional tool (eg Tim Ferris and Tony Hsieh) so they can afford to spend more money, but a literary writer is actually trying to make money from selling books. That's not to say there's not value in paying to get to the top of fiction for better visibility or that it also doesn't happen.