As a luncheon meat, Spam is a bargain. As unsolicited marketing, spam is a rip-off: $712 per employee per year, or $71 billon to all U.S. businesses annually.

That's the cost of spam in terms of lost productivity, according to a survey released Monday by IT research firms Nucleus Research and KnowledgeStorm.

These figures come from a survey of 849 e-mail users conducted last month that found that two of every three e-mail messages received by businesspeople are spam, despite the fact that 60% of companies filter spam. The survey results are based on a $30-per-hour pay rate, a 2,080-hour work year, 100,249,046 U.S. e-mail-using workers, and that e-mail users are spending 16 seconds on average identifying and deleting spam that has evaded detection and landed in an in-box.

While 16 seconds may seem like an extraordinarily long time to ascertain whether a message titled, say, "DEAR BELOVE FRIEND" or "Attention: Winner" is spam, Rebecca Wettemann, VP of Research of Nucleus Research, said that's the amount of time reported by survey respondents.

It is, surprisingly, a marked decrease in the amount of time Nucleus Research survey respondents wrote off to spam in 2004. That year, e-mail users said it took them 30 seconds to identify and delete spam, putting the annual cost of spam at $1,934 per employee.

Asked if this decline in the cost of spam to businesses demonstrated the value of anti-spam technology, Wettemann was skeptical. "Spam filtering helps," she said. "However, the spammers keep getting smarter and more innovative in the way they're getting around filtering technology."

For spammers, evolution may be necessary for survival, both from a business perspective and from a personal perspective. The survey indicates that frustration with spam has risen to the point where 18% of respondents said spammers should be jailed, with a third of those in favor of sentences longer than 36 months.

When provided with an "Other" option on questions about spammer punishment, respondents filled in the blank with suggestions that included "the death penalty, slow hanging [lowered gently from the gallows until the rope is taut?], public flogging, psychological assessment, and other responses that are inappropriate to print." From this, the survey concludes that nine out of 10 e-mail users are frustrated with spam and one in 100 "appear to be at the breaking point."

Whether spammers will ever really face the rage expressed in this survey remains to be seen. But given that 17% of respondents identified unsolicited e-mail from family and friends as spam, we all might be well advised to sleep with one eye open.