Unsolicited commercial e-mail could cost US companies $874 (£526) per employee a year in lost productivity, according to a report by independent research company Nucleus Research.
The report, entitled "Spam: The Silent ROI Killer" contains the results of interviews with employees and IT administrators at 76 different US companies.
The $874 figure is based on an hourly pay of $30 and a work year of 2,080 hours, Nucleus said.
Among the other findings of the report are the following:
- Companies lose approximately 1.4% of each employee's productivity each year because of spam.
- The average employee receives 13.3 spam messages each day.
- Employees spend, on average, 6.5 minutes a day managing spam.
Most recently, Network Associates released a survey of 1,500 online participants that found users spending 40 minutes a week dealing with spam.
Joe Fisher, director of product management at Tumbleweed Communications, a supplier of antispam products, said the cost may be even higher.
"I would argue it's a bit higher, depending on the organisation. I think the industry-accepted standard is approximately $20 or $25 per hour per employee," Fisher said.
Still, many of the studies, so far, have focused on the volume of the spam rather than its effect on business productivity, according to Ian Campbell, chief executive officer of Nucleus.
"We didn't see any study that dealt with productivity... questions like, 'If I employ a spam filter, how much time do I get back?', or 'Am I blocking messages that are costing me time to deal with?'" Campbell said.
Among the 117 employees surveyed, Nucleus researchers looked for users with varying exposure to the spam problem, Campbell said.
Nucleus interviewed users with e-mail addresses that had been harvested by spammers multiple times and who were "besieged" by spam, as well as those with addresses that had little exposure to the public internet and so were unknown to most spammers, and "normal users" who fell in between the two extremes.
A potentially controversial conclusion of the survey was that spam filtering technology does not lead to significant improvements in productivity.
"Filtering stops some more e-mail messages, but it only saves about 26% of the productivity loss, so the cost of spam with filters is not significantly less than without it," Campbell said.
The sophistication of spammers relative to antispam technology and a lack of a consistent education of employees about the problem are partly to blame for the ineffectiveness of filtering, Nucleus said.
Although the study still recommends that companies deploy spam-filtering products, other methods may yield better results, Campbell said.
Campbell said recent legal action against alleged spammers by Microsoft and others is, potentially, more effective than antispam technology and recommended that concerned businesses owners call their congressional representative.
"You're in a technology war with the spammers. Filtering will help, but there's nothing that helps more than a couple years in jail," he said.
Nucleus is hoping that the survey raises eyebrows in the business community, noting that for every 72 employees, companies are losing the productivity of one because of spam.
"If one of out of every 72 of your employees showed up to work and slept all day, you'd be upset about that, but you're losing that productivity simply because you do not have spam coming through," Campbell said.
Paul Roberts writes for IDG News Service