In 2005, American workers spent the equivalent of 2.3 million years' worth of 40-hour workweeks reading nonwork-related blogs while at work, according to a study by Advertising Age magazine. And that's just blogs. Millions more work years were spent shopping online, checking eBay listings, cruising social networks, looking for vacation deals, Googling old flames, and, of course, ogling porn. A 2005 survey by America Online and concluded that employers spend nearly $760 billion a year paying employees to goof off on the Web.

It would seem that there's an enormous opportunity here to recover all this lost productivity. And don't think your fellow captains of industry aren't trying: According to a 2005 study from the American Management Association and the ePolicy Institute, more than three-quarters of all companies monitor their employees' Web use, and 36 percent even record what employees pull up on their screens and what they type on their keyboards. Such companies must be way more productive than their less attentive peers, right? Not necessarily.

That's because in the Internet age, the very concept of productivity is being redefined, and wrestling with this change will be one of the biggest challenges entrepreneurs will face in the years to come. (Let's put aside for a moment the matter of the potential harm an employee can cause by visiting sites trafficking in pornography, racism, gambling, or music downloads.) The fact is, employees have always engaged in certain types of wide-net information-gathering activities that don't directly feed the bottom line but are considered reasonable uses of time: attending trade shows, reading magazines, hanging out by the water cooler. Now we've got an ocean of information--the Internet--and what do you know, a lot of people like to spend lots of time trolling through it. But that doesn't make them unproductive.

For one thing, the line between at-work and off-work is growing increasingly blurry. Thanks to cell phones, BlackBerrys, and ubiquitous high-speed Internet access, many employees are as productive at home as they are when they're behind their desks. In fact, such off-hours activity more than makes up for productivity that is "lost" to leisurely Web surfing between 9 and 5, says Robert Cenek, a human resources expert who publishes the Cenek Report, an online journal. "Employees tend to spend more time doing work-related Internet tasks at home than nonwork-related Internet tasks at the office," he says. Indeed, employees spend an average of 3.7 hours a week on the Web for personal activities at work and 5.9 hours a week online at home doing work-related tasks, according to a study by the University of Maryland's Smith School of Business and Rockbridge Associates, a market research firm based in Great Falls, Virginia.

"It's not realistic to think you can control everything employees do online, and it feels punitive to watch over them."

Of course, that argument assumes that nonwork-related Web use is by its nature unproductive. I don't see it that way. An employee who spends 15 minutes straightening out her online banking, 20 minutes booking a vacation, and half an hour looking at real estate websites may be an employee who doesn't take off an afternoon to stop by the bank and the travel agent and a bunch of open houses.

Perhaps more important, recreational Web surfing has become a kind of mental floss for workers who spend their days sucking in a stream of work-related data that now comes in at a firehose pace--it's the information age equivalent of a walk around the block. Simply put, workers, especially knowledge workers, may need a certain amount of distraction during the day to keep from burning out, and Web surfing fills the bill. It's one of the laws of thermodynamics: Prodigious output is always accompanied by a lot of wasted energy.

Ask yourself this question: If there's a surprising, hot new trend emerging out there somewhere just waiting to be exploited by an aggressive entrepreneur, who's more likely to discover it and call it to your attention, the employee who spends every minute of the workday focused on his prescribed chores or the one who spends some time bouncing around various websites checking out whatever looks interesting? I think you know the answer. (For a different approach, see Street Smarts.)

I can hear the teeth-gnashing already. And it's understandable. The argument for restricting Web surfing is compelling, and there are some pretty sophisticated tools to do it. San Diego-based Websense offers software that groups some 15 million webpages into more than 90 categories--including swimsuit/lingerie and sports gambling--so that a company can cut off access to certain websites on a surgical basis. Websense even allows clients to allocate a specified number of daily minutes to each employee to spend on different groups of websites before cutting off access. "A fairly common window is about half an hour each day," says Michael Newman, the company's vice president and general counsel. Scott Montgomery, a vice president at Secure Computing, a San Jose, California, company that offers a competing product called Webwasher, claims the software often pays for itself the first day in rescued productivity.

But there's a lot more to this question than dollars and cents. A heavy-handed approach to controlling Internet use almost always leads to unhappy and resentful employees--and real productivity losses. Cracking down on Web surfing is often seen as invasive and narrow-minded--and often by employees who are the most critical contributors. For every few hours of "productivity" you gain this way, you risk losing some of the people and ideas you need the most. "It's not realistic to think you can control everything employees do online, and it feels punitive to watch over them," says Kit Murphy, COO of Chester Willcox & Saxbe LLP, a Columbus, Ohio-based law firm with 70 employees. "It's not good for morale." Murphy notes that while the firm will question employees' excessive use of the Internet if their productivity plunges, it runs no software designed to limit anyone's access to websites. And that's smart business, says Gartner analyst David Smith, because limiting online access can scare away top job candidates. "I've seen companies lose out on good job candidates because they don't consider the work environment progressive enough, based on not getting the online access they wanted," Smith says. "And we're seeing more people like that enter the work force."

Are there situations where controlling Web access may make sense? Sure. Employees doing relatively rote work sensitive to inefficiency costs, such as call-center agents or assembly-line workers, would have trouble making the case that they need to wile away chunks of their shifts watching videos on YouTube. Some companies block access to certain kinds of websites as a way to keep viruses out of their computer systems or reduce the risk of lawsuits.

But there are plenty of high-tech tools that do that without limiting the freedom to Web surf, such as antivirus programs and firewalls. A better approach is to spell out loudly and clearly what sort of Web surfing is asking for trouble and why. Employees who go ahead with their wicked surfing anyway will probably come to management's attention before anything truly terrible happens, assuming management has any idea of what is going on at the company.

Which brings me to the most important point of all. If you have a significant percentage of employees who are genuinely shirking their responsibilities via constant, mindless Web surfing, you really should consider the possibility that open Web access isn't even close to being your biggest problem. As HR expert Cenek puts it: "Folks ought to be working hard because they're attracted to the work they're doing." And management's key job is make sure employees are motivated in this way. Face it. You aren't going to resolve the problem of an unscrupulous, unmotivated organization by trying to identify and cut off access to every possible website an employee might want to waste time at. And if you think you can, then I think I see where the problem lies.

Contributing editor David H. Freedman ( is a Boston-based author of several books about business and technology.