Some critics of the Arctic Monkeys claim their typiccal fan would be 15-25 years old and probably male, such as the person who made this slide show. This is probably true of thier first 2 albums altleast, however, they were both number 1 in the UK charts. this means that more people would have heard their songs and the audience range would swell.
 While they always had a big following, especially in the UK, their audience swelled dramatically when they headlined glastonbury in 2013.
As their first album, Whatever People Say, That's What I'm Not, came out in 2006, their original fans have grown up, making them a band whose audience spans across 2 generations. They also span across genres, being labelled as Indie rock psychedelic rock, garage rock, post-punk revival and post-britpop. They also take inspiration from hip-hop, with Alex Turner claiming "It (AM) sounds like a Dr Dre beat, but we've given it an Ike Turner bowl-cut and sent it galloping across the desert on a Stratocaster."  this gives hip-hop fans a gateway into thier Indie Rock genre by giving them some familiarity, not making the music too alien to any 1 genre.