Now, one of the Internet's best-known jesters is getting serious.

As chief executive of a rapidly growing startup called AdBrite, Kaplan hopes to disrupt the status quo and strike it rich, just like all the dot-com dreamers he once ridiculed mercilessly.

"I decided I wanted to change my life drastically," Kaplan said. "I can't sleep in until noon and just goof off whenever I want anymore."

Kaplan, 29, moved to San Francisco from New York late last year, planting AdBrite and its 15 employees in the same neighborhood that became a dot-com graveyard a few years ago.

"If you are going to be a movie star, you have to go to Hollywood, and if you are going to try to build an Internet business, you have to be in Silicon Valley," Kaplan said.

He already has navigated a significant rite of passage by raising $4 million from Sequoia Capital, a leading area venture capital firm that has funded such successes as Apple Computer Inc., Yahoo Inc. and Google Inc.

Doors quickly opened when Kaplan came knocking. Venture capitalists, like almost everyone else in the high-tech industry, know him from his days skewering dot-coms. It didn't take long for Sequoia Capital partner Mark Kvamme to conclude Kaplan's business acumen may be even keener than his sense of humor.

"He has all the instincts of a high-quality entrepreneur," Kvamme said, citing Kaplan's ability to capitalize on the dot-com meltdown and then conceive a business plan to profit from the dot-com comeback.

Richard Kyanka, an AdBrite customer who runs SomethingAwful.com, puts it this way: Kaplan "is just one of those guys who can spot an opportunity and know how to take advantage of it."

AdBrite spun out of FC, Kaplan's online spoof of Fast Company, one of several high-tech magazines that profiled the rapid rise of Internet startups during the late 1990s.

The satirical site focused on the mania's inane side. Filled with tart remarks and insider tidbits, Kaplan's site attracted as many as 4 million visitors per month, helping him attract advertisers.

Looking to minimize his workload, Kaplan created a program to automate advertising sales. That program eventually evolved into AdBrite.

Online advertising is ripening almost as quickly as dot-coms were rotting when Kaplan started to trash rancid companies.

About $11.5 billion has been budgeted for Internet advertising this year, nearly doubling the $6 billion spent in 2002, according to eMarketer, an online research firm.

Much of it goes to keyword ads, which are distributed based on how much bidders are willing to pay to be linked to specific terms used in a search engine request. For instance, entering the word "mortgage" might produce text-based ads from lenders who agreed to pay Google or Yahoo $10 each time a user clicks on the sponsored link.

Although this system is profitable, it requires advertisers to spend a lot of time monitoring the bidding to ensure their links still have a good chance of being displayed. Participating Web sites also have little control over the types of ads shown.

AdBrite offers an alternative. Web site publishers set a fixed ad price, no matter how frequently the links get clicked. Potential advertisers are able to select the sites most compatible with their marketing objectives.

Web sites can also reject ads that could offend their target audiences. That's the main reason the professional networking Web site LinkedIn has so far turned away roughly half of the advertisers that have tried to buy spots through AdBrite, said Konstantin Guericke, LinkedIn's vice president of marketing.

"Making sure we don't turn anyone off is more important to us than trying to get as much advertising as possible," Guericke said.

Because AdBrite remains privately held, Kaplan won't disclose the company's finances other than to say sales have been increasing by 20 percent to 40 percent each month.

AdBrite's network currently spans about 3,400 Web sites, generating more than 100 million daily page views.

Kaplan is managing AdBrite cautiously, knowing many people would delight in his failure.

Kaplan considers himself very frugal — a trait that Kvamme also has noticed. The venture capitalist says his firm sometimes has to prod Kaplan to hire more workers.

AdBrite's Spartan offices rent for less than $5,000 per month — cheaper than the plasma TVs that some free-spending Internet businesses slapped on their walls during the boom years.

A single pingpong table provides the sole recreation for the entire office. Kaplan keeps a set of drums by his desk, as well as a magazine cover shot that featured him in 2001 when he was nearing the pinnacle of his dot-com-bashing fame.

Kaplan no longer spends time on his satirical site, having turned the writing duties over to a woman who he says isn't nearly as funny as he.

But can Kaplan be a serious success?