I am not much into art, but something I read in a Stephen King novel about a painter always resonated with me: You are not selling the picture but the story behind the picture. Whoever is interested in your picture, if you can tell them an inspiring tale about the circumstances it was created in your chance of a sale will increase manifold. Of course this is from a storytellers point out view so you can assume an emphasis on stories, but it kind of makes sense: If you show someone a picture you bought they might appreciate for the arts sake alone, but a good story is a bonus that will make this exact picture stand out. So if you wanna sell pictures, have a good story to tell about each.