However, the reality is that almost everyone listens to the same artists and songs all the time. If you take anyone's iPod and check the "Most played" list, it will contain less than 5% of the whole library. Go on, try it, I can wait.
It turns out that we like things that we know, things we are familiar with.
Radio stations have known that for a long time. You know when people call the station to ask for a song? Did you notice that they never ask for an obscure one, a song they haven't heard since high school? It's always the same song that played 4 times in the last 2 hours.
Once I read a very good article about a TV show for small children, 3 year olds or so. They spent a lot of time doing studies and discovered that the kids loved to see the same show again and again (actually, any parent knows that - there is no limit to how many times a kid can watch Wall-E...). So what did they do? Showed the same episode of the show every day of the week. Kids loved it, the producer became a millionaire and parents wanted to shoot themselves in the heads.
And this is why, if one year ago I told you that it would be a good idea to make a movie about a farmer managing his little farm and buying crops and building barns, you would say I'm crazy. Now, if someone starts discussing a possible FarmVille movie, it turns out it might make a lot of sense. It's not a movie about a farm - It's FarmVille.