Teen Web sensation MySpace became so big so fast, News Corp. spent $580 million last year to buy it. Then Google Inc. struck a $900 million deal, primarily to advertise with it. But now Jackie Birnbaum and her fellow English classmates at Falls Church High School say they’re over MySpace, the Washington Post reports.

“I think it’s definitely going down — a lot of my friends have deleted their MySpaces and are more into Facebook now,” said Birnbaum, a junior who spends more time on her Facebook profile, where she messages and shares photos with other students in her network.

From the other side of the classroom, E.J. Kim chimes in that in the past three months, she’s gone from slaving over her MySpace profile up to four hours a day — decorating it, posting notes and pictures to her friends’ pages — to deleting the whole thing.

“I’ve grown out of it,” Kim said. “I thought it was kind of pointless.”

Such is the social life of teens on the Internet: Powerful but fickle. Within several months’ time, a site can garner tens of millions of users who, just as quickly, might flock to the next place, making it hard for corporate America to make lasting investments in whatever’s hot now.

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