I personally think this would have limited use to buyers because only hardcore industry veterans would likely know enough to understand how this works. It is hard enough to get some photo buyers to understand the basic concept of image licensing to begin with. The plus side is that you can theoretically protect your copyrighted work a little better since the license would be embedded in the meta data. Given all of the Orphan Works b.s. that is happening in Congress, you can never be too safe.
Photoshelter’s payment and distribution options are pretty similar to LicenseStream’s but the difference is that the photo buyer can’t look for another photographer’s images on the site. This is a pretty big deal because whenever you send an instant license via Photoshelter you risk losing sales to other photographers if they decide to browse the Photoshelter home page out of curiosity. On the LicenseStream home page, there is no such site-wide archive search.
If you’re interested in seeing it for yourself, check out my LicenseStream gallery.