those who follow the mainstream artists such as 50cent, or Justin Timberlake for example, Have no life what-so-ever.
I don't know that this is accurate, necessarily. However, when it comes to people who follow mainstream artists, a lot of sheep imagery comes to mind - the flock follows whatever artists the media is holding up at the time. I know quite a few people who used to listen to N*SYNC (gag me!), and at the time thought they were the greatest band in the world. Now, it's whoever else is popular - they never even put on an old album because it's simply not popular anymore.
In a way, this is why music on the internet is gaining such popularity - instead of going out and buying a cd, people can download whatever music is popular at the time. It's less of an investment than going out and buying the entire album, and it's not as permanent.