Art dealers use color images to signal the availability of their inventory.
A dealer might have hundreds, even thousands, of unique works of art, each requiring a separate image. Over time, art dealers have used printed invitations, catalogs, and advertisements to communicate with collectors outside the gallery. In addition to color photography, dealers routinely pay for slides and transparencies, dupes, color separations, printing, postage, and, of course, advertising, not to mention staff. These costs continue to escalate. Publishing on the Web is almost instantaneous.