Quote - What I would like to see for promo renders are:

1. Neutral lighting -- all lights white. (Except for things which come with lights.) This is especially important when looking at figure textures. My prefered setup when I'm trying to compare different skin textures, morphs, whatever during character development (for my own purposes) is typically a pure white IBL with AO at about 30%, and an infinite white light coming from above and to one side at about 80%.
2. Figures should be shown in front view, profile, and 3/4 view.
3. Outside products should be listed. (If nothing else, so that I know what they are so I can buy them if they look really cool. :))

And

Quote - 4. Hair should have a good full side and back view;

5. Bare bones renders should be on the first 3 pages of the ad. A 4th page should be added so that the vendor can showcase the product in a full gallery-style image to give the potential buyer a sense of what can be done.  Those types of images should not be in the thumbnail or first image on the first page.

Are EXCELLENT suggestions.

I think packaging white-renders, profiles and "best results" type images are completely necessary if one wants to truly give the customer a good opportunity to judge the product.  Any other products used in the image need to be named as well.  This is also a marketing opportunity as well and benefits other artists and their distributors.