A Black or White Backgrounds only relationship to lighting is in the way you light  your subject to bring out the detail you that is needed.  An Illustration or Painting is a different animal all together. They  let your imagination fill in the detail that sometimes disapears into its dark or light background with the purpose of bringing out drama, or mystery.  

In selling a product, Black or white backgrounds are also an excellent way to show off your products. And if you have 3 or 4 Illustrations as examples, At least two should give you good detail of the subject. There is nothing wrong with bringing out drama or supence with some detail disapearing into the background with a few examples, as long as you can see some detail of your other examples.

 To clairify one thing, It's not that you use a black or a white as a background. It is that you show good detail of your subject in doing so, somewhere with your examples. Almost all the merchants that I see do a great job in doing so. Just look how they show off their product with there backgrounds and learn how to sell your product with good lighting.