Anders,
Since my previous post, I've discovered that I have made a sale, to Travel & Leisure Golf, of an image where the buyer independently searched the PhotoShelter archives. It looks like one or two other buyers have downloaded comps as a result of searches.
My hope is that as more and more PhotoShelter photographers promote the site to their clients, it will gain recognition as a source of quality stock photography, even if PS itself does little or no marketing to position itself as a portal. That seemed to be happening with Digital Railroad, and a lot of DRR photographers have moved to PhotoShelter.
- Greg