College senior Alyssa Ravasio gave up MySpace on the day she got a Facebook account and never looked back. She has already lost interest in Twitter. But how does Facebook know it can keep her loyalty?

The brief history of the internet is littered with the ghosts of websites that people have abandoned in their relentless pursuit of something newer, faster, better and cooler.

Tech-savvy Ravasio, a 21-year-old UCLA student designing her undergraduate degree around the internet's impact on society and communication, is irked by changes privately owned Facebook has made.

But for now, she says, Facebook is keeping her allegiance because of a concept called "technological lock-in". In other words, the site has become an essential part of her life.

"I think Facebook is the most valuable internet commodity in existence, more so than Google, because they are positioning themselves to be our online identity via Facebook connect," Mr Ravasio said.

"It's your real name, it's your real friends, and assuming they manage to navigate the privacy quagmire, they're poised to become your universal login," she said. "I would almost argue that Facebook is the new mobile phone. It's the new thing you need to keep in touch, almost a requirement of modern social life."

Technological lock-in is the idea that the more a society adopts a certain technology, the more unlikely users are to switch. It's the reason why the QWERTY keyboard layout, devised for typewriters in the 1870s, is still the standard despite the development of several more logical configurations.