Hey poppy, I watched your video, as well as a couple others of yours. I actually had more fun watching the funny faces on since I like peoples expressions anyway. I did find the one you posted a bit repetitious, and long because of that. Nice pictures, but just too many of the same to keep someones interest for the 4 minute runtime.
I really don't think there is much of a market for slideshows per se, unless it's created around a person or subject, and for them specifically. Ie, taking images of a model for her portfolio, an event or wedding, or portraits for a client, and then creating a slideshow for them has market potential. But I don't think a show of a generic subject, such as flowers, landscapes, sunsets, etc, has as much resale potential.