People always offer accounts for 2 or 3 dollars. How do they do it?

I've been here for about a week, and I've noticed something and it annoys me. I got hold of a bunch of porn accounts (I know), and I didn't want or need them so I decided I would sell them here. I thought this would be an easy business, but it's not. Everywhere I see "Origin Accounts for .$.75!" or "Minecraft accounts, one dollar each!" How?!

I know people are doing this for their business, and I know they are cracked accounts, but where do they gain this knowledge. I feel like everyone deserves to know. People buy accounts for one or two bucks and think they got a great deal, when really they probably could've got twice what they paid for for free. It just annoys me, and it seems like the only way to get them is to either buy a program to do it for 30 bucks, or an ebook on how to do it for 15.

I think it's time that everyone finds out how to crack accounts and get keys for games. I know what gets them, but I want to know how to get the programs to get them.

TLDR: Can somebody link us to an ebook/account cracker and tell us how to do it in detail as if we were 5? We deserve to know.