THE Facebook juggernaut has claimed the scalp of AOL Time Warner's $US850 million ($921 million) acquisition of Bebo, with the social media site tipped to close its Australian operation before Christmas as part of a global retreat and rethink.

Bebo's woes follow the troubles Facebook has inflicted on News Corp's one-time darling MySpace, which has been forced to reposition itself as a leader in the online music area and let Facebook dominate the service of broader social networking.

Australians, unlike net users in many other markets, have rapidly given Google and Facebook a near-monopoly position in online search and social networking.

The extent of Facebook's reach in Australia - it accounts for 29 per cent of all time spent online by Australians - has led to research group Nielsen defining the trend as "Facebook Time" and "Non Facebook Time".

"It's just phenomenal," said Nielsen Online's director of analytics, Mark Higginson. "Every time I run those numbers I have to double check. Australians are spending nearly a third of all their time browsing the internet on Facebook alone."