Certain forums place bounties on a book, and when someone uploads it they collect that bounty. It’s a sort of internal points system for that forum. So someone will put up a bounty post, other interested users will also pledge, someone will obtain and upload the book to a file hosting site, and collect the bounty.
Some titles at least one person will have to buy. Other don’t even cost anything, as it is trivial to rip a Kindle Unlimited book if you know what you’re doing.
Using terms like ‘u’, ‘ur’, etc when writing. No one charges by the letter, it’s simply lazy.