Twitter, says Constantine Von Hoffman this week on eMedia Vitals, is a dead-end technology. Why? Because young people don’t use it:

“Just 7% of those between 12 and 17 use Twitter, according to a Quantcast study. These numbers appear to improve with the next age group: 47% of those between 18 and 34 are Twitterers. However, the median age of a Twitter user is 31, according to a Pew study. This means most of the people on Twitter are 25+. By comparison, the median ages of MySpace and Facebook users are 27 and 26, respectively. (And, just as you suspected, LinkedIn is for fogies – median age: 40.)”

I won’t argue with his conclusion that Twitter is doomed. It may well die off or evolve into something unrecognizable within a few years. But I don’t buy the death-by-demographics argument. Just because people in one age group don’t do something now doesn’t necessarily mean they won’t later in life.

There is a key difference between this and a more persuasive demographic argument earlier this week from Alan Mutter. His topic was the death not of Twitter, but of newspapers.

Mutter cited data that show “there is little doubt that consumer demand for newspapers is likely to decline as the population ages.” People under 50 are far less likely to read newspapers than those over 50, he noted. Therefore, “unless something unforeseeable happens to change the news-consumption habits of younger readers, it stands to reason that the total audience of newspaper readers will shrink as the older generation dies off.”

The key word here is habits. The assumption is that older people still read the newspaper not because it is the best way to get news, but because it’s a long-term habit. For younger people, by contrast, reading newspapers has not become an ingrained habit, and they can make more rational decisions about how to get news. Presumably, if you looked at the same statistics from 1960, you’d see a much higher proportion of young people reading newspapers.*

When it comes to Twitter, however, you can’t argue that use is related to habit. Twitter is in fact newer than either Facebook or MySpace. If it tends to be used predominantly by people over 30, the reason cannot be force of habit. More likely, it’s that people in that age group find it genuinely useful. So who’s to say that those young people who have no use for Twitter now won’t change their minds as they mature?

* Or would you? As one of Mutter’s commenters noted, “it would be enormously helpful to see a historical graph illustrating readership levels, by age, in 2000, 1990, 1980, etc.,” to see whether in fact “younger newspaper readers been outnumbered by their elders all along,” and “if so, by what margin, compared to today?”