You must be familiar with the milkman, although this occupation is long gone. During the fifties and sixties, the milkman were a common sight, and much like the famous ice-cream trucks, people used to wait for the milk truck to come around. Milkmen delivered milk jars to front doors mostly in the suburbs, as if they were daily newspapers.
What ultimately put an end to the milkmen occupation were the refrigerators – as they became a household essential, demand for fresh milk every day decreased. Milkmen continued to deliver milk to customers in the US until the mid seventies, and since then, demand has almost completely stopped.