IDG Books Worldwide VP-Marketing John Kilcullen could never be called dumb. But his marketing brainchild positions itself as being just that.

A former sales director at Bantam Electronic Publishing, Mr. Kilcullen, 36, overheard a frustrated consumer saying he needed a simple computer book, something like "DOS for dummies." The idea stuck in his head, and years later when he was VP-marketing at International Data Group's book publishing arm, he pitched the idea to IDG. Since 1991, more than 100 titles have been published including "DOS for Dummies," "Taxes for Dummies" and "Internet for Dummies." They've have sold more than 20 million copies around the world with translations in 26 languages, and have taken IDG Books from strictly a publisher of computer books into the realm of general interest publishing.

"We think learning should be fun," says Mr. Kilcullen. "Wherever there's a difficult or intimidating subject, the Dummies brand should be the first antidote to that frustration."

In fact, the company has more than 200 "For Dummies" titles on tap for the next year, including a "Sex for Dummies" written by Dr. Ruth Westheimer and even a possible "Bible for Dummies."

The company projects the series sales will reach $250 million by the year 2000.

The key to selling the books, which typically sell for $16.95, is some unconventional marketing. Playing off the bold yellow-and-black book covers, the company has sponsored contests and sweepstakes promotions including giving away a yellow Mazda Miata, a trip to Yellowstone Park and a number of yellow underwater cameras.

The publisher gave away thousands of free copies of "Taxes for Dummies" at post offices April 15, and inflates a 20-foot version of its quirky "Dummy" icon of a nerdish-looking character at publishing trade shows and book store openings.

"We're basically the first publisher who's been able to mass-market technical information," says Mr. Kilcullen. "And we think our brand can become as widely known as Sony."