Judging from the ongoing hype, the social networking service that I love to deplore is used by, well, just about everybody.

In fact, I just got a report from a consulting firm called Edison Research that shows that, well, just about everybody at least has heard of Twitter.

…we can report that awareness of Twitter is nearly universal - in fact, it’s difficult to see how it could be much higher. Awareness of Twitter amongst Americans 12+ currently stands at 92%.

But how many people actually use Twitter?

Hmmm….

Twitter usage, on the other hand, does have significant room for growth. This year, we are reporting that eight percent of Americans 12+ are current users of Twitter, up one percentage point from last year.

“Significant room for growth”—that’s one way to look at it. The other is that the vast majority of the country knows about this free service and has chosen not to use it.

Now, eight percent of Americans is a lot of people, and there’s no question that in some contexts many people find Twitter entertaining and (during the occasional revolution, what have you) useful.

But unlike with Facebook, in my opinion, most people still don’t feel that they derive enough value from Twitter tho make it worth their time. I’d bet that if you ran the numbers on Twitter users, you’d find 50% were under the age of 20, 80% under the age of 30, and the other ten percent work in public relations and marketing.

Maybe in the long run this will mean that, as young people get older, they will keep using Twitter and its use will become more pervasive among adults. And it certainly means that Twitter can provide access to a desirable (from a marketer’s point of view) audience of young consumers.

But I’d bet it’s just as likely that Twitter stays marginalized among tech geeks, PR people and the young—like MTV. And I’d say there’s a decent chance that something else (or somethings) comes along to either replace it or chip away at its social networking status….