A survey in Britain has estimated that Twitter, Facebook and other social networking sites are costing the economy there £14 billion (€16.85 billion) a year. Lord knows what the equivalent figure comes to in Ireland considering our prodigious use of such sites, but we’d imagine that any survey here would mirror the main findings of the MyJobGroup study.

They found that over half of British employees admitted to updating their personal Twitter, Facebook and MySpace profiles while at work, while a third said they spent half an hour a day using the websites.

Two million people – or 6% of Britain’s 34 million-strong workforce – admitted wasting more than an hour every day adding friends, uploading pictures and videos and tweeting. The resulting drop in workers’ productivity could be costing British businesses as much as £14 billion a year, according to an analysis by MyJobGroup (who are actually a network of jobs websites).

Over 1,000 people were surveyed and a report in The Telegraph notes that many of them are still in denial with only 14% of those question admitting to being less productive as a result of social media, and 10% claiming that using Facebook and Twitter at work boosted their productivity. Of course it does, I bet all their bosses agree too.

Anyway, Lee Fayer, managing director of MyJobGroup said: “Our results clearly show that UK workers are spending increased time whilst at work on social media networks, which, left unchecked, could have negative repercussions on the productivity of many companies across the country.

Fayer added, “Companies would do well to monitor use of social networking sites during work hours and ensure that their employees are not abusing their freedom of access to these sites.”