And models are also more timeless.

"People are getting afraid that actors are only as hot as their last movie or TV show," says Faith Kates, founder of Next Model Management in New York. Kates expects her firm to see a 15 percent to 20 percent increase in revenue this year as a result of supermodels' return. Besides, she adds, "models don't show up with an entourage."

Luxury labels, of course, aren't swearing off celebrities cold turkey. Dressing stars for their red-carpet appearances remains a fundamental tactic. The free clothes that fashion houses often lavish on stars help perpetuate the practice. Versace itself frequently dresses actresses, including Jessica Alba, who wore Versace to the Golden Globes and the Oscars this year. The company says it doesn't pay Alba to wear Versace but does "lend" her clothes.