It seems that we may finally all be suffering Facebook fatigue.

According to The Times, Facebook has suffered its first monthly drop in visitor numbers since its launch.

The website, which is the most popular social networking site in the UK, had enjoyed a 17 successive month boom.

But, between December and Janaury, Facebook suffered a 5% dip in visitors - from 8.9 million to 8.5 million.

Despite this, Facebook's audience was still 712% greater in January this year than in the same month last year, and up 10% on the previous quarter.

But it seems other social networking sites are suffering too.

The UK's second most popular social networking website, MySpace, also saw visitor figures drop 5%, taking it down to 5 million, while Bebo, the third largest, dropped 2% to 4.1 million, showed figures published by Nielsen Online.

Networks on Yahoo and Google-owned sites experienced falls of 16% and 30% respectively, while Piczo has lost 56% of its audience in the past year.

"Facebook was never going to be able to carry on growing the way it has, and a lot of people - especially those who've been using it heavily - are now starting to get Facebook fatigue", Alex Burmaster, an internet analyst at Nielsen Online told The Times.

"I think when something explodes like that a lot of people check it out because they feel they should, but while getting alerts about what your friends are up to is exciting for a time, that's inevitably going to die down."

Burmaster suggested that growth on the bigger social networking websites will level out this year but the popularity of niche sites will continue to grow as their visitors are more "engaged".

He pointed to WAYN (Where Are You Now), a travel networking site whose UK audience has grown 25% in the past year to 461,000, as well as LinkedIn, the professional network, which jumped from 161,000 to 433,000.