Many of us asks ourselves the same question: What subject sells the most? I have learned from little experience that the answer to this question lies in the statistics of our own Portfolios. Most of the time the number of views, or better yet sales, that your images get tells you how interesting the subject of your image is.
For Example my Best Seller:
This is the most viewed and sold image on my Portfolio. This actually tells me all the keywords that are being used in order to search for images and also the subject that people are looking to buy. This is why variety is a very important key here. I know I just have 29 uploads but believe me the learning experience is great and it does motivate to keep on shooting. Thanks for reading and great sales to everyone.