RE: SPS Flywheel and How to Get There
We've already got an enormous amount of Art we can use for skins.
Splinterlands Art contest winners. Get the permission of the artist, or make it a condition of entry that winning entries will be licensed by Splinterlands and receive an x% royalty on skin sales.
The mechanics might be a difficult thing to implement (as the devs are busy working on other things) - but the pay off for the community and the artists involved is ongoing, instead of a once upon a time prize.