I remember when Halo 3 came out, one of my friends parents went out of the country during the summer holidays. They all (4 guys) slept over at his house and would play Halo 3 day and night. They were really good at it.
Than Halo: Reach came out we played it for like 2 weeks and they were quite disappointed at the game. I personally didn't like the Halo games, the fact wasn't that wasn't good at the game but it was just not my gameplay type. Maybe I just didn't play as much but I also knew a guy who would make these accounts and get the highest level for Halo and sell the account to people