I'm in the print-on-demand business. The listings we generate always include a size chart. My observation is that almost nobody ever looks at them. For whateve

I'm in the print-on-demand business. The listings we generate always include a size chart. My observation is that almost nobody ever looks at them. For whatever reason, people just assume "I'm a S" or "I'm a L" and borderline cases search reviews for "it runs small" or "it runs large". Women's sizes are sometimes numbered (because, of course, women only vary on a single dimension).