One thing that makes a great photo is its ability to convey emotion. Emotion in a photograph, or any work of art, is what helps a viewer connect with a piece if that emotion is prevalent in the viewer. Emotion, or a feeling, is what can bring a snapshot out of obscurity and make it shine.
What Sells Best On Shutterstock?
Some types of photos that sell best are Portrait Photography, Food Photography, Landscapes (usually with people) and fine art photography (artsy).