The question is, does Facebook behave like Google, or even more generally, like e-mail, and last a long time, or is it just another 4-5 year fad? If its a longer term tool then the behavioral trends of young demographics are a big deal.
Strongly disagree. Teens grow up. Demands on their time changes. Later on they maybe get married, get houses, kids. Life priorities change. Other platforms, tools offer a better fit for their altered circumstances. They move on.
I'll predict that a couple of years from now, the main population left on FB will be 60- somethings who once again are at a stage in their lives where they can afford the time for it.
Maybe - though my guess is that they'll join a university population and/or workforce and start interacting with the wider world, that just happens to be significantly on Facebook. But at 40 mine is hardly a relevant opinion :)
As a 20-something, email still has an important place for official communication. Email is to texting/Facebook message what dead-tree letters are to email.
My guess is that the teenager/young adult demographic is highly coveted by advertisers because they tend to have disposable income (gross generalization) and are the most vocal/enthusiastic customers. they can act like 3d billboards for whatever they happen to be into. idk just a guess
Do teenagers spend money online? Is there any research on that?