Why do so many teenagers have cell-phones?

They're everywhere. At the store, in the car, at the gym, at school and even at church-sponsored activities. More and more teenagers are getting cell-phones and taking them on like a permament part of their daily self. Why do so many teenagers have cell-phones.
Parents continue to buy the devices for their children. It's become easier and more affordable to have more than one per household. "Family plans" have become quite popular. Even then, it doesn't seem necessary for half of the junior high population to be in possession of their own phone. Why is it necessary? In most cases it isn't a need, but a want. It's a desire to have what others have, to be accepted by the "text-messagers," to look cool in front of friends and simply to have something of worldly value for one's self. There isn't anything wrong with these desires. The point is only that in most cases cell-phones for young teenagers are a want rather than a need.
I'll admit that I have a cell-phone of my own. However, I didn't get it until after I turned sixteen. I wanted it for safety purposes as I started to drive on my own. My parents and I wanted to be able to communicate, and it comes in quite handy. I did not receive a phone beofre I was responsible enough and had good reason. It was also something that I purchased on my own. I paid for my phone, plan and minutes. It has been nice to have a phone, but it wasn't necessary until I got my driver's lisense.
When parents have cell-phones, it's cheap and easy to add their children to their plan. Then they can call each other for free. They can contact their children in case of an emergency. For ten dollars a month, they can ensure their ability to communicate with their kids. This is a very good reason for a child to have a cell-phone. The convenience, security and price make buying a cell-phone for a teenager very easy. While this may be the persuasion used to convince the parents, it is not the usual reason that teens desire a phone of their own.
Teenagers are getting more and more cell-phones every day. In public schools, more have them don't. Why so many? It's affordable, easy, convenient, secure, "cool," fun and it's what everyone else would seem to have. Parents buy them for the right reasons, but most teenagers seem to want them for the superficial reasons. Well, I guess that most teenagers will be teenagers.