For many people who upload to POD websites (Print on Demand), there can be many questions from new members who are joining them, but one of those comments and questions most frequently asked is, things like "I have been here for 6 months and I have not made any sales. Why is that?"
Easy answer - There can be many thousands of other members on the very same POD website as yourself, fighting for the very same position as you are and that is to try and hit the top of those searches and have the "right" images that customers are searching for. Images must be of a great quality and for some people, they must be of a memorable location that customers have visited and such like and want to retain those memories for future years to come, but, these POD websites are not the places to "Get Rich Quick" LOL
Because these POD websites will be doing all of the hard work for you (Printing, Building of Frames and Canvases etc, Shipping, Customer Services and Queries and such like), you will ONLY receive a commission on your work. Some POD Websites will allow you to set your own mark up, but their prices will go higher, the higher your mark up goes. Other POD websites will add their own "percentage" that you will receive, once a sale has been completed, with usually a 30 day holding period, which is required to allow for returns and exchanges.
Sales can be very few and far between, but when it happens it can be a bit of an ego boost and a bonus, none the less.