It may be the fastest selling, but that doesn't really mean all that much. If they get more albums sold than the Beatles then I really will eat my hat. It basically shows that they managed to set up their band well. They worked from all the tiniest bars in Sheffield, gradually building up to the bigger venues, building a huge fanbase just from their live work. Their album is no-where near as good as their live performances, and it's their live performances that people are buying the album from.
It just shows how clever the music business is really.
Timmy P