It took me years to convince my mom (whom I usually share a booth with) to try a comic convention instead of craft fairs. I've never been shy about my opinion of craft fairs (the only people that go to craft fairs are crafters lol). We did the first one and she was hooked! At the last one we went to in May I didn't do great because I haven't been cutting much (bronchitis and sawdust don't mesh well of course) but she made around $600, and it was a small local con (about 2000 attendees, only one day.).
I also like that conventions tend to have rules for vendors, such as no pyramid party type sales (avon, Tupperware, etc) and ideally your product should appeal to the target audience. The one we went to was general fandoms, so everything geeky did well, especially superheroes (my mom and I both crochet, she was selling beanies at that one, I had a few puzzles out and took some orders)
If you have the time and money, definitely worth looking into, especially local conventions that are trying to get started (we paid $75 for two tables for one day and we wrapped at 4 pm)