Fridge not cooling, ice building at the back of the freezer compartment, fan noise. He has seen this five hundred times — it is the defrost system, it is a forty-minute job, and he does not have the part on the van.
So it becomes a diagnostic fee, a parts order, and a second visit next week. Two drives, two appointment slots, one job's revenue. The margin on that call is gone, and the customer — who has now lived out of a cooler for six days — is not going to describe you warmly to her neighbour.
The difference between that call and a profitable one is a sticker inside a fridge door.
Now consider what actually happened. When that customer rang, she was standing in her kitchen, about three feet from a sticker inside the fridge door with the full model number printed on it. Ninety seconds of the right questions and your tech would have driven out with the part on the van and finished it in one visit.
That is the specific thing that makes appliance repair different from every other trade around it. In plumbing, the phone call is a booking. Here the phone call is a parts-ordering conversation, and whoever takes it determines whether the job is profitable before anybody gets in a truck.
Which is why voicemail is unusually expensive in this trade. It is not simply that the caller rings the next company — though they do, because a family with a dead fridge full of food is not waiting. It is that even the calls you do win, won badly, come back as second trips.
And the volume arrives when nobody is free: evenings and weekends, when people use their appliances and discover the washing machine has stopped mid-cycle with the door locked and a drum full of water.