In August, the site's share of teens 12 to 17 dropped to 11.9% from 24.7% year over year, while internet users between the ages of 35 and 54 -- not exactly trendsetters -- now account for 40.6% of the MySpace visitor base, an 8.2% increase during the past year.
"The brand is bound to get old," said Gartner Research analyst Andrew Frank. "That's why Fox Interactive is developing MySpace as a platform for services and delivering content."
Whether MySpace can survive without teens isn't clear. "Staying relevant and hot among teens is a really tough game, but if they lose their edge there, I think they're in trouble," said Allen Adamson of Landor Associates, a branding consultancy in New York. "While it's nice that they're picking up steam among older users, they're going to have a tough time if they lose young trendsetters."
Older MySpace members tend to be less active in the community. This month, the average 12- to 17-year-old spent 260 minutes on MySpace and viewed about 808 pages. By contrast, the average 35- to 54-year-old spent 179 minutes on the site and took in 560 pages.
"The market tends to overreact to numbers like this," Mr. Frank added, "but I wouldn't count out the possibility that MySpace has reached its peak."
MySpace drew 79.6 million unique visitors in August, according to ComScore World Metrix, an impressive 243% increase year over year.
News Corp. is using MySpace to push everything from movies and TV shows to soft drinks and mobile phones. Earlier this week, Fox loaded the site with already-aired episodes from the current season of "Bones," "Prison Break," "Standoff," "Vanished," "Justice," "Talk Show With Spike Feresten," "'Til Death" and "The Loop." Those shows are being supported initially by ads from Toyota, Burger King and Lions Gate Films.
Young-adult members of MySpace, 18- to-24-year-olds, dropped 1.4% to 18.1% from a 19.6% share. The block, made up of 25- to 34-year-olds, meanwhile, grew 6.2% from 10.4% to 16.7% of MySpace users.
Facebook.com, which began as a social-networking site for college students, is still drawing a younger audience, according to ComScore. More than a third of visitors to Facebook.com are 18 to 24, about three times the representation of that age segment in the general internet population.
A fifth of the social site Xanga.com is made up of 12- to 17-year-olds, about twice as high as that age segment's representation, according to ComScore.