During January 2011 social networks accounted for 12.4% of all UK Internet visits, according to figures compiled by Experian Hitwise.

"Across the 9000 social networks that we monitor, there were over 2.4 billion visits from UK Internet users during the month - more than in any other month on record," says the company.

Not only are people visiting social sites more regularly, says Experian, but the time they spend on these Websites is increasing, with the average session time running to 22 minutes.

While Facebook may be the dominant social network in the UK, accounting for 56% of traffic to the industry during January, Experian found significant interaction between different social sites, as users dart between multiple networks.

One in every eight people leaving a social network visits another one immediately after, says Experian. Facebook is a key source of traffic for many smaller social networks; while almost a fifth of people leaving Twitter go on to visit another social network.

Social networks have become a key source of traffic from many online businesses, particularly those distributing content and chasing 'eyeballs'. But transactional Websites - those selling goods or services such as travel or insurance online - still rely primarily on search for their traffic and therefore sales.

"Successful transactional Websites will be those that learn to harness the power of social networks, driving traffic through to their own Websites," says the Experian report.

Businesses are catching up with the trend, with one-third of UK companies now embracing the medium, according to a survey of 5000 companies conducted by Virgin Media. The study discovered that 32% of firms are now using Websites such as Twitter and Facebook as part of their marketing and communication policies

Finextra is partnering with Thomson Reuters and leading financial services firms to develop a series of one-day events exploring the use of social media within the financial services sector. The first two social media days - in London on 7 April, and New York on 18 May - feature speakers from banksimple, StockTwits, CME Group, Citi, HSBC, SEB and First Direct.