Workers in the U.S will this year waste the equivalent of 551,000 years reading blogs, a study has suggested.
The research by Advertising Age magazine has calculated that some 35 million workers, about one in four of the U.S labour force, will read blogs and visit blog sites during the year.
On average they will spend 3.5 hours, or 9 per cent, of their working week engaged with them.
Time spent in the office on non-work blogs this year will take up the equivalent of 2.3 million jobs, with blog readers essentially taking a daily 40-minute "blog break".
While blogs are becoming an accepted part of the media, and are increasingly being harnessed by marketers, they are increasingly sapping employees' time and eating into the time they give their employers, the magazine found.
Christopher Batty, sales director of blog site Gawker Media, said: "The Gawker audience is very at-work; it's an at-work, leisure audience, in other words, people screwing off [taking time out] on the job."
Most bosses accept that allowing some time for non-work related activity in the office – emails, surfing, the occasional personal call and so on – is a quid pro quo for keeping employees happy, motivated and promoting camaraderie.
But Andy Sernovitz, chief executive of the Word of Mouth Marketing Association, said blogs had become the favoured diversion for "office goof-off time", although there is an overlap in that many blogs will bounce readers to professional media sites.
But at the end of the day more blogging means less working, argued Jonathan Gibs, senior research manager at Nielsen/NetRatings.
At-work blog time probably comes in addition to regular surfing, meaning more time on the Web but less time on the job.
"Since for the most part blog readers tend to be the most engaged readers of online content, they do not appear, at least for now, to be sacrificing time from their favourite news sites," he said.
"Instead, it looks like blog usage is in addition to existing online behaviour," he added.
While some blogs do relate to work, but deciding just how relevant they are to the employer is open to debate.
But with blogging increasing in Europe as well as in the U.S, the magazine's estimates will make chilling reading for many employers.
It calculated that work time spent reading and posting to blogs this year will consume 2.2 per cent of U.S. labour force hours.
Work time spent at blogs unrelated to work will eat up 1.65 per cent of labour force hours.
U.S. workers this year will waste the equivalent of 551,000 years (based on a 24-hour day) or 2.3 million work years (based on a typical nearly 40-hour work week) reading blogs unrelated to their job.
"Traffic rockets at 8 a.m. EST, peaks at 5 p.m. EST and then slides downward until L.A. leaves the office," said Henry Copeland, founder of blog advertising site Blogads.
"You see the same thing in the collapse of traffic on weekends. … Bottom line: At work, people can't watch TV or prop up their feet and read a newspaper, but they sure do read blogs," he added.