It's a good sign when someone calls you to say that a friend bought them some of your cupcakes and they were the best they'd ever had. And that they'd tell everyone they knew.
Or when you drop off LOTS of boxes of cupcakes to a soup kitchen and the wonderful young ladies (Yale students, I think) who are hard at work making lunches and dinner for their guests get really excited about the arrival of a cupcake bakeshop in the area.
Those are good signs, right?