We spend a lot of ink on nights and overflow. That is because those are the hours owners forget to price. It does not follow that every trade business should skip a person at the desk. The plumbing supply counter in Oakland Park that also runs a service arm is a different animal from a three-van after-hours leak shop.
The tell is the lobby
If customers actually walk in — warranty parts, a water heater they want to see, a contractor picking up a fixture — you need a human who can look someone in the eye and open a drawer. That work does not belong on a phone tree. It belongs to someone who knows which aisle the 3/4 fittings live on.
Steady daytime volume is still a job
If the log shows 40-plus live conversations between 8 and 4, most of them not emergencies, a hire is often cheaper than pretending the owner can do both. The mistake is hiring that person and then also expecting them to cover Saturday generator calls. Those are two jobs. Pay for the one you actually have in the lobby, and be honest about the rest of the week.