ok, looking at the last numbers in gt series, with less than 25 million consoles sold... all of them sold more than 2 millions first week... against more than 3 millions sold for halo series first week...
so my first thought is that comparing first week sales, if GT5 can get 10m it's going to be a long race to that mark, that i'm sure it will reach because every GT game has reached that mark.
now, looking at the lifetime sales GT3, the best selling game in GT series, sold 15m in its lifespan against 10m for halo 3, with just 2 years in its lifespan. now i don't think that halo can reach that mark in its whole lifetime since the series never sold more than that.
so, if you look at the sales, GT could easily pass that mark, i don't know if it could be the bestseller HD game, but it's the only one that can reach that right now, aside from halo:reach.
I'm Back! - Proud owner of the best doomed handheld of all time!
