Apple's decision makes business sense, analysts say. Rather than spend a lot of money on the trade show, the company can reach customers directly through its retail stores and can put on its own special events.
Baker said Apple isn't the only tech vendor moving away from trade shows as a way to reach customers. "Trade shows in general are on the decline," he said, noting that many of the shows he attended this year, even before the economic slowdown took hold, were smaller than in previous years.
Companies are finding less expensive ways to get their message out through the Web and their own special events, Baker said. "Trade shows in general are starting to use some of the clout in the market."
Apple's absence, however, has brought even more uncertainty to the future of the San Francisco conference, which is expected to attract 40,000 people this year. When Apple pulled out of Macworld Boston in 2003, the show closed two years later.
IDG believes the San Francisco event can continue without Apple, given that it remains a showcase for developers and third-party vendors who are part of the Apple ecosystem. Besides offering a product showroom, Macworld also has training sessions for developers and is a major networking event.
IDG on Dec. 30 said it would hold a "town hall meeting" at Macworld for attendees who want to provide input on how future events should be organized.
Meanwhile, Jobs' absence has sparked fear among the Mac faithful that he could be gravely ill. Jobs battled pancreatic cancer four years ago and has said he is cancer free. However, answers about his health were revealed Monday when Jobs wrote a letter saying he was recovering from a hormone imbalance. Apple's board issued a statement within minutes confirming that Jobs would remain on as CEO until the charismatic leader decides to step down.
Macworld continues this week until Friday.