when I was little we didn't een have a TV lol. We got our first TV when I was 12 (and it was black/white :/ ) and didn't get our first computer until I was 15...
my half-brother on the other hand is 6 years younger than me, so to him the TV has been about from the age of 6. 10 years later and he has a TV in his room and more games consels then you can immagine... he has 2 PS2s for gods sake, why do you need 2?

He goes to school each day and when he gets in runs upstairs and locks hisself in his room for the rest of the night. He will not even eat dinner unless it's taken to him in his room... He'll be there fixed to the screen until 10 or 11 at night, then get up at 6 so he can fit in a few hours before school... and that is his life...
it seriouslly depresses me... whenever I visit I try to get him to do other things, but he gets actually violent over it...
I think what happens is parents see it as an easy way to keep children occupied while they get stuff like work done. But then as time goes on it gets more and more tempting just to appease the child with TV...