I had my 7D and Canon 70-200 2.8 lens waiting on a Christmas show to start at Dollywood. Due to the very low lighting this was the only lens I had that would work and my wife wanted a couple of pictures.
Just before the show was to begin I was approached by a female who ask why and who I was taking pictures for. She said I must be a professional with lens like that. She then ask if I could take some of her daughter who was in the show. All she had was an ipad and it would not take pictures in low light. She was more than willing to pay me for this service.