Lands' End, which started selling custom-made pants online a year ago, says 40% of jean and chino sales on its Web site are now custom orders. That means consumers mix and match fabrics, styles and colors.

Nike, meanwhile, says 20% of sneaker sales on its Nike iD Web site are customized. And customization efforts are shifting into higher gear at Ford Motor and among European automakers.

The companies say letting customers design products from the get-go cuts waste, design time and inventory costs. That's just the strategy Dell deployed to become the personal computer industry's most successful player.

For consumers, the phenomenon means more choices, more unique clothing — but at a higher cost and a longer wait.

"It's one of the most significant technology advances in the apparel industry," says Bill Bass, senior vice president of e-commerce at Lands' End. "No one can afford not to use it."