As well as the news that Facebook is used by half the UK population, Facebook also laid bare its vision for the future of the social web in a keynote at the UK's largest digital marketing event, TFM&A.

Stephen Haines, commercial director for Facebook in the UK, said that the site would continue to evolve.

"There have been eight iterations of the [main] Facebook design over the last few years... [and] it will look different in a year" he said, clearly intimating that the site would continue to change to enhance its commercial succcess.

The site has never been slow to change fundamentals of its design and approach, most recently with the redesign of the Like button.

"The average Facebook user has 130 friends [and] the average time spent on Facebook is 28 minutes a day."

Haines also showed impressive figures showing the effectiveness of brand pages. The official Starbucks page on Facebook boasts 21.1 million users compared to 1.8m website visitors. Coke's page is even more extreme – 20.5m users compared to 270,000 website visitors a month.

He hailed the success of Facebook Deals, which had even crashed the Alton Towers website. Then Haines talked up the value of social advertising. "There's a 68 per cent increase in recall when an ad has a social context," said Haines. Ads with a poll are currently some of the most popular, he suggested.

Haines also suggested the social network could look to keep users within its walls by offering branded stores for buying goods online. He also talked about the idea of "social by design", saying that GM was now even introducing Facebook streams within some of its car models.

And Facebook also seems to be on the rise for display advertising. According to eMarketer research, the social network's share of ads will rise to nearly 22.6 per cent of its total revenue.

From browsing to discovery

Haines also surprised the audience by saying that "the fastest growing Facebook audience is the over-35s". However, we guess it's not so surprising when you consider that practically everybody younger than that has an account.

Haines also explained that there are now more over 40s than 13 to 18 year olds on Facebook and talked up the opportunities for marketers within this demographic.

A slide was shown, which Haines explained as the fact "the web is now organising around people and their connections". He explained this by showing the 90s as a "browsing" period, the 00s as the "searching" period and the current decade as a time to "discover".

Messages boost?

In a busy day for the social network, Facebook has also announced the purchase of private group messaging startup Beluga – it's a bit like Google Wave in that it's effectively private messaging inside a selected group. Indeed, the founders of Beluga previously worked at the Big G. Beluga could be incorporated inside Facebook Messages.

The web is also rife with speculation that Facebook is pushing ahead with its controversial plan to allow developers access to users' personal information if permitted, such as their phone numbers. The plan was originally dropped after an outcry, but now appears to be back on the cards.

Facebook now has 30 million UK users and boasts more than 500 million users worldwide. What's perhaps most impressive is the site's stickiness. Over 15 million of Facebook's UK users visit every single day. Amusingly, Haines confessed that he didn't use Facebook four years ago when he was interviewed for his current post.