We did a beast of a pickup and delivery job yesterday that I had to take a loss on. The customer bought some very large items that were extremely heavy and had to come downstairs so we had to take a lot of extra time and care. We had to bring an extra guy and the whole thing took an extra hour and 20 minutes from what I had estimated. She also lived down a tiny road that was difficult to get out truck down.
Even though I had quoted her am hourly rate vs a flat rate, I let the customer know that it would have normally cost XXX but that I was discounting it to the price she and I had discussed.
She was very grateful and said, "what I didn't tell you is that we have 12 rental properties and we have a junk removal company that we usually use but we will be calling you in the future!"
Something like that certainly takes a loss and turns it into a win.