We would like to be able to generate a GIF from the 3d models we have on our account. We think it would be a great addition to the premium accounts.
Edit: the reason for that is that sketchfab is difficult to share. For example sketchfab on Facebook PC shows embedded in the timeline, but on phones it takes the user to a new page. From our survey, users then cancel the page loading and go back to Facebook.
We think that a gif would generate more interest, and clicking on the gif could then send to the 3d model page on sketchfab.
The gif could be a full turntable, or a bounce left-right that would make people understand the 3d model.