Since no one has to be home for my winterizings, I may not see a customer for years. One customer sold his house, and when the new owner called, I told him where to find the indoor shutoff, and that I'd deal with the rest. Standard operating procedure. What wasn't standard, was that I ran out of invoices and door-hanger envelopes, and didn't leave an invoice behind after that winterizing. What was also not standard, was the phone message a day later complaining of the price I quoted, and the (insulting) counteroffer. After the steam stopped coming from my ears, I pondered what would be the best thing to do. And I did it. Nothing. No phone call. No mailed invoice. I was hoping he'd pay someone to come winterize the system, and see nothing but air coming from the sprinkler heads, and just maybe, my diabolical plan would come to fruition. I would have to wait at least a year, but I could hope. And more than a year later, I had another phone message from the cheapskate. ~ "Everything's broken!" (system had anti-syphon valves) ~ I forget whether I gave a fist pump, or just smiled.