Today A has a dancing party. I told the kids the story of when I had a moving disco business during high school (in Venezuela). We would take our huge stereos, lights, music, etc. to parties and make pretty good money. It was the early eighties and we played disco music. We once got a call asking us if we played Salsa & Merengue. We said yes and were hired - but did not have a single merengue or salsa album. We went to a record store and bought a bunch of salsa and merengue records. As you might imagine, the party was a disaster. We had no clue about which songs to play, and, worst still, we didn't know that you don't mix one salsa song with the next (the way you do for disco). The lesson? Stick to what you know. For everyone's sake!
I sometimes get calls from prospective customers. They are willing to give me money, but I know they are not the "right" customers for me and I turn them down. It is hard turning business down, but it is sometimes the right thing to do. You don't want unhappy customers.