the unique selling position should be obvious.
For Steemians, we love other Steemians and Steemian products and services.
With my proposed stock image site, I would enable Steem photogs to make Steem currency directly. For the Steemian blogger, there is an innate trust of other Steemians who produce artwork. And as a Steemian project, my site would have significant advantage over any stock photo site. Furthermore, the "cheetah" style bot will be pointing people to my site.
In other words.... it will be sufficiently unique to acquire new users daily.