The hype leading up to the launch of Apple’s iPhone began a full six months before the product ever hit store shelves, when Apple CEO Steve Jobs officially christened it “the next big thing” at a January trade show in San Francisco.

The media obliged, devoting hours of air time and reams of newsprint to the high-tech gadget. “Gotta-be-first-with-anything-new” consumers obediently played their part, lining up overnight to shell out $500 or $600 for the new gadget (and providing yet more fodder for the “news” outlets).

All the hype clearly had an impact on Apple’s stock, to the tune of a 40% run-up over a matter of months. But in late July, the hangover hit. Sales figures for the new iPhone did not live up to analysts’ expectations, and there was an immediate sell-off in Apple stock.

So did the company make a big mistake with all the pre-rollout hype? Would it have fared better had it played the launch closer to the vest? Maybe, maybe not.

When all was said and done, Apple still sold a huge number of what reviewers have generally deemed a competent but not life-changing electronic device, and it projected sales of 1 million iPhones by the end of the third quarter. Still, the experience illustrates the danger of over-hyping a future new product release and not being able to live up to the promise.

“I am and always have been a huge fan of Apple products, but I just don’t understand the kind of coverage the iPhone was getting months before the product even shipped,” says Guy Kawasaki, managing director of Garage Technology Ventures and a former Apple Fellow at Apple Computer, Inc.

Some marketing experts also question the validity of Apple’s approach. Jehoshua Eliashberg, a Marketing Professor at the Wharton School, points out that companies tip off their competitors when they pre-announce a new product introduction, especially as far before the launch as Apple did.

Christophe Van den Bulte, another Wharton Marketing Professor, agrees with his colleague but stresses that there are many variables to consider in choosing a launch strategy. They included the nature of the target market, the manufacturer’s dependence on partners (Apple blamed cellular carrier AT&T for problems in getting the new phones activated, for example), and the buying cycle of the product itself.

“In general, the more consumable a product, the shorter its buying cycle, and it makes sense not to announce those launch plans too early,” Van den Bulte says. “Pre-announcement makes more sense for durable goods that last a number of years.”

Research conducted at Michigan State University suggests that the companies most likely to pre-announce new products are those positioned as icons in their industry. They are confident in the security of their competitive position and often pre-announce in an attempt to forge a direction for the industry, garner support for their thought leadership and set the stage for future moves.