GTA V never ceases to amaze me, you'd think that everybody that wants the game already owns it but the damn game keeps selling like hot cakes.
I bet a lot of it has to do with people double-dipping between the last-gen & current-gen versions when they upgrade their hardware. One of the rare occasions where the game really deserves a second look on current platforms as the shift from last to current gen is night and day between the two.
Rockstar was brilliant in releasing V during the sunset of last gen and then bringing it back, Bigger, Badder & More Badass for current gen.