I have sold print on demand items for 4 years on Etsy on two separate shops. I hit a time when I was doing awesome, and thought I could ramp up my game by improving titles and changing my SEO. But in doing so, I completely screwed the whole thing up. Now, almost 2 years later, I have not fully recovered and only make a couple sales per week if I am lucky. Etsy is a sensitive beast. I’m much happier writing for medium where I know that I don’t have to drive my own traffic and I just have to be myself and put out good content. My shops are still up but I put little effort into them these days.