Sometimes the answer to the question "why am I not getting any commissions" is simply "your work doesn't stand out/isn't quite there yet".

It's rarely the ONLY problem, but sometimes it really is the biggest problem. It's just a really rough thing to say so I usually don't.

On the upside, this is something you can (and IMO always should) work on. Art is a field with a slow pay-off. It really is. It's never going to make you rich unless you're very lucky (so lol @ the "get rich quick" schemes), but keep honing your skills and it WILL pay off.