How many scenes are better?

What do you think, what slideshow will sell best: with 10 or 20 scenes?

If you mean how many different scenes in a footage clip the answer is 1. Since the beginning of Pond5 they have said to do only one scene per clip. If you have several "parts" divide them up into individual clips to sell.

Thanks for your reply, but maybe I should make myself clear: I mean slideshows as After Effects templates.