Honestly, I found the robot sales completely by accident, but the best clues were understanding my customers. It's a process, for sure. I discovered that most people who buy my robot illustrations are people in the 30-50 age range (give or take), self-professed quirky people and nerds who like to be silly and enjoy humorous art. I also learned that my work was priced too low at first because everyone bought them in pairs, and kept coming back to buy more. When I raised my prices $5, I got more customers in the door, who actually bought more than two robots, and sometimes paintings with their robot order. I had one middle aged woman buy from me twice because her son collects robots, and she thought my work was funny.
All these experiences form a basis for your target market. Another big help is looking at your shop stats to see who is favoriting and searching for your work. If you have a Facebook page or Google Analytics account, you can actually see the age range, country, etc. of the people who look at your work, and that gives further clues. I admit it takes some time and I am STILL learning more every day. Best of luck to everyone!
