Its called earning money from others fame. Now check for any famous website name people have taken such miss spelled names.
Lot of visistors coming to those famous sites and when they miss type the URL they get in to such sites and when they click on something they get paid. Easy money making method from other peoples fame.
Now as an example if i take yajoo.com name when ppl miss spell letter h with j they come to my site. since h and j are one after the other in the keyboard that can happen. So i get free money. If you check yajoo.com for real , Yahoo already has taken that name and saying you are typing wrong URL and corerct one is yahoo.com
We dont have money to take miss type domains like that so other people using them to earn money. Thats it! hehe nothing about hacking or anything. Those are simple money making tricks on the internet.