Chances are your inbox is filled with e-mails you intend to read one day: Customer satisfaction surveys. Airline flight bargains. Product sales announcements. All those newsletters you wish you'd never signed up for.

It's not exactly spam, because you asked for it. But it's not personal e-mail either. For better or worse, this undefined category of e-mail now has a name -- bacn (pronounced bacon).

"To me, it's a bit tastier than spam. It's relevant e-mail you've opted to receive either by signing up for a service, joining a Web site or subscribing to content," said Andrew Foote, head of the digital marketing division of Peppercom, a New York-based public relations firm.

The term bacn is a relatively new expression first brought to life on Aug. 20 at a blog conference at the Art Institute of Pittsburgh -- PodCamp Pittsburgh 2. Almost instantly, the term spread across the Web and claimed a place in Internet lingo.

Bacn is a form of self-inflicted spam. You don't mind receiving news alerts or updates from your bank, or your favorite Web sites. But just as too much bacon can clog the arteries, too much bacn can jam an inbox.

Richard Laermer, author of "Punk Marketing," thinks bacn could be the beginning of the end for e-mail.

"Having an e-mail box will become so much trouble for people at some point they'll say forget it," said the New York-based author.

"We'll go to a form of instant messaging where you approve people to contact you," Mr. Laermer said. "After that falls apart, we'll go back to the phone. That's a means of communication that has yet to fail us."

Though it seems innocent enough, bacn can be hazardous to your computer's health, said Jess Kalish, director of corporate and technical communications at Boynton Beach, Fla.-based iS3, makers of STOPzilla anti-spyware.

She said some people who send spam will try to trick you into thinking it's bacn. If you open the link it could be a malicious Web site that downloads spyware onto your computer.

"Spam. Bacn. These are very cutesy names that can result in identity theft," Ms. Kalish said. "And there's nothing cute about that."

Moira Hardek, a mission specialist with the Geek Squad, a division of Best Buy, in Minneapolis, said she and other Geek Squad agents spend a lot of time removing viruses from computers as a result of people innocently mistaking spam for bacn.

"The borderline between spam and bacn can cause major problems with computers," Ms. Hardek said.

For online marketers, bacn is the bread and butter of their business.

Thomas Harpointer, chief executive of Atlanta-based AIS media, said his company did an Internet usage survey recently that found 61 percent of consumers are receptive to receiving e-mail notifications from preferred venders instead of postal mail.

Still, it often can take a long time for people to get around to reading their bacn. Week after week it piles up like a stack of old magazines. The challenge for online marketers is to figure how frequently to send bacn to people who have requested it.

"If you send it too often people stop reading, but if you don't send it often enough they lose interest," said Larry Weintraub, CEO of Fanscape a Los Angeles-based new media marketing agency.

"We've finally lessened the spam issue," Mr. Weintraub said. "Now we've got to deal with getting too much information on stuff we want to know about."