Luxury Retailers get Online Store Religion

What does luxury mean in a world where anyone, it seems, can readily purchase "luxury" goods. Does a Rolex watch still inspire awe? A Jil Sander suit?

From the NY Times:

Not long ago, said Federico Marchetti, the founder of Yoox, a company in Milan that runs retailing sites for luxury brands like Valentino, Emilio Pucci and Jil Sander, “there was a lot of skepticism.”
“Now,” he said, “it is the opposite.”

How can advertisers of luxury products differentiate when one of the key tenets of luxury is exclusivity?