IN October, Cartier held a free exhibition at its Fifth Avenue flagship that displayed its newest haute joaillerie collection, Résonances de Cartier, as well as archival pieces once owned by Elizabeth Taylor and the Duchess of Windsor.

"It's like meeting famous people in real life," said Katie Sutton, 24, of Ames, Iowa. "You see it in the movies, you see it in pictures, but to see it in real life, it blows you away, to see how amazing and how big they are, to see the quality and to see how it's made." On this particular sunny afternoon, Sutton was walking through the display in the Manhattan store with her sister, Teran Stark, who lives in Queens. Stark had heard about the exhibition on Facebook.

In the past, such collections were heralded by invitations printed on snowy-white correspondence cards, addressed in calligraphy and sent to the rich and the worthy. Jewellery houses created displays in rented hôtels particuliers or their own salons, placing new creations on velvet or Perspex stands, lighting for twinkle. And, of course, there was champagne.