Employees in the UK are now so fascinated with Facebook that they access it more often than any other single website or service, including, incredibly, Google search.

According to Network Box’s latest 14 billion URL survey of traffic through its managed servers, Facebook now consumes 4.5 percent of corporate bandwidth, or just over 7 percent of all outward business traffic, equivalent to over a billion hits and rising in the second quarter.  

Only the video-based YouTube beats Facebook for corporate bandwidth consumption, consuming a startling 10.2 percent, but in terms of visits, Google is still some way behind on 3.9 percent.

Other notable bandwidth consumers include Yahoo’s image server, Yimg, which uses 2.9 percent of bandwidth and generated 2.9 percent of hits, and Windows updates, which accounts for 2.3 percent of hits.

Leaving aside search engines, which can claim to have legitimate business uses, it is clear that traffic to consumer websites such as Facebook and YouTube is now a major use for business networks whether companies approve or not.

 “Fifteen percent of available corporate bandwidth is used by websites that are probably not being used for business purposes,” said Simon Heron of Network Box.

“Although many businesses now use social networks for work, it’s unlikely that they’re the top working priority for most employees. Clearly human factors, such as the desire to socialise while at work, play a large part.”

Last November Network Box published its previous traffic survey and found much the same pattern of bandwidth consumption by unofficial apps such as YouTube and Facebook, but the new figures are different in one important way - the percentage of consumed bandwidth has now risen sharply.