Pictures that do sell and do not (personal experience)
By this moment I have 242 sales, which include different types of images. There are some facts I've found...
Artistic pictures like these above that took a great deal of time usually sell very bad (and mostly - by subscription) or don't sell at all. This is a biggest disappointment, to be sure. But there are two exceptions that brought me 21$ and 18$ when others - zero or usually 0.42$
Sketches sell surprisingly well, even when their colored variants have no sales at all.
Borders and frames sell well if hand drawn and don't sell at all if they are collage or vector
Crayon drawings (I have few of them) sell very good. All they have at least 1 sale. These two shown above have 4 and 6 sales.
The fact that childish art can be sold was a great surprise to me. I've uploaded 29 images I've found in our family archive and 7 of them have found their buyers already.
My collages do not sell. These two have 1 and 2 sales, another picture has 1, others 36 are still at zero.
These photos have 4 sales each, others were not so lucky. I'm a poor photographer, I know. Photos are the factor that keeps my acceptance ration at 58%
I also have some watercolors and they are doing well, so it's a pity I have no opportunity to make more right now.
And my vectors were just a waste of time. I'm not going to make any more of them.