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.

the  artic monkeys signed to domino, an independant label in July 2005. http://dominorecordco.com/artists/arctic-monkeys/. they have recorded 5 albums, all of whick were UK no1's. As well as selling well, all the albums were well recieved by critics:
http://www.metacritic.com/music/whatever-people-say-i-am-thats-what-im-not/arctic-monkeys
http://www.metacritic.com/music/favourite-worst-nightmare/arctic-monkeys
http://www.metacritic.com/music/humbug/arctic-monkeys
http://www.metacritic.com/music/suck-it-and-see/arctic-monkeys
http://www.metacritic.com/music/am/arctic-monkeys

Response to the Arctic Monkeys has been consistently good from both the general public and critics, especially in the UK. While the UK is the country where they are biggest, the Arctic Monkeys also have an impressive international record, especially with their last album 'AM' which went no1 in 7 countries.

Critics have also been kind to the Arctic Monkeys, with Metacritic  giving AM a combined score of 81/100, including NME and No Ripcord giving 100/100.

Recording/ production
The Arctic Monkey's last album ,AM, was recorded live in a rehearsal room, with some instruments dubbed over later. James Ford, the Arctic Monkey's producer explains here, that the befit of recording this way was that they could record something a soon as they thought of  it. Recording this way can also make the artist play with energy that they would live and can make for a more exciting album.

James Ford describes the way in which he produces the Arctic Monkeys as 'back yo basics'. They record their tracks on tape, meaning not of post editing can be done, for example auto-tune wouldn't be possible.

In an interview with sound on sound, James Ford explains that he prefers a natural sound, and this is the reason for recording in Sound City studios, L.A. In this interview, he also explains that recording an producing with the band is a collaborative processes in terms deciding on the texture of the song, and also the structure of the songs and where they are placed on the albums. The amount of input he has into the songs has labeled him the 5th Arctic Monkey, showing exactly how important he is in creating the end product.

promoting themselves.
The Arctic Monkeys use Facebook and Twitter, always posting their gigs and tour dates. This is a great way to reach their target audience as they are of the right age to get the most from online media.
They also have a soundcloud account with a link to Itunes.This lets everyone stream some of their music for free and is a good way of letting people hear what kind of music they make online, without it making it easy to download for free like people are known to do in Youtube.
Through the years, the Arctic Monkeys have also appeared in a lot of magazines including NME, Q, and SPIN.
they also appear on a lot of interviews both as a group with NME and Q, but also as individuals such as this Alex Turner interview and Matt Helders interview.
This constant media attention grabs their target audience and constantly reminds them to listen to them. I believe this is what separates them from a lot of Indie bands that have faded out.
Another thing that keeps the Arctic Monkeys is popular view is that fact that they aren't afraid of controversy. They have done a lot of interviews and shows where they have been critiqued for their 'ireverance' such as in this video where they are accused of 'going ape' and on Soccer AM where Alex Turner shows of his fake I.D. This kind of controversy appeals to a lot of their target audience, especially the younger end of their audience as they would probably going through their teenage rebellion phase.
A massive way of promotion for any band is through live gigs, which the Arctic Monkeys thrive on, playing Glastonbury, Itunes Festival and set in the Radio 1 Lounge, all in 2013. Each of these shows have a massive fan base and plenty off listeners, increasing the amount of people who will hear them play and possibley buy their albums. This combined with playing the 2012 Olympic Ceremony has put them in the general public's eyeline.