UltimateGamer1982 on 02 January 2016
The XB1 is nowhere near as popular as the 360 was when halo 3 came out, plus you had a lot of former PlayStation users jump ship back then which also helped increase sales.
But things have changed a lot since 2007. Bungie no longer makes halo, nor is the series the juggernaut it once was, due in part to 343 turning off a sizable percentage of old users with halo 4 and MCC.
The game still sells better than many other games however, but it's certainly a franchise that is past its prime and is in major decline as a whole.
