Web users in the U.K. spent 65% more time online in April 2010 (884 million hours) than they did in April 2007 (536 million hours), according to UKOM (The U.K. Online Measurement Company), a media industry measurement of U.K. consumers’ online activity delivered by Nielsen. Although overall Internet time is up, the way folks in the U.K. have allocated their web time has changed dramatically.

In April 2007, Social Networks & Blogs accounted for less than nine percent of all UK Internet time, but in three years the sector has grown to account for almost 23 percent of U.K. Internet time – the equivalent of one in every four and a half minutes. In other words, if all April 2010 U.K. Internet Time were condensed into one hour, 13 1/2 minutes would have been spent on Social Networks & Blogs.

The most heavily used sectors following Social Networks & Blogs are personal (non-work) Email (56 million hours / 7.2 percent share of time) and Online Games (53 million hours / 6.9 percent share).

The biggest casualty of the rise in social networking is Instant Messaging (IM) which, three years ago, was the most heavily used sector but has since dropped below Email and Online Games. IM’s share of U.K. Internet time has fallen from 14 percent to five percent – a relative drop of 66 percent. In contrast, personal Email, which many predicted to be another casualty of the social networking phenomenon, has actually increased its share of online time from 6.5 percent to 7.2 percent – a relative rise of 11 percent.

“Despite the large increase in the amount of time people spend online and the increasing proliferation of websites and online services, one thing has remained constant and that is the bulk of time accounted for by communicating, networking and playing games,” said Alex Burmaster, VP of Global Communications for Nielsen's Online division. “These are the pillars on which the Internet as a heavily used medium are built.”