What is the sales era?

By The Book:
Sales era is the era from 1920 to the early 1950s in which, the manufacturers began to increase their emphasis on effective sales forces to find customers for their output. In this era,firms attempted to match their output to the potential number of customers who would want it.

My Definition:
The sales era is the era in history from 1920 to the early 1950s, in which manufacturers realized that the innovative production apparatus created huge surplus, so they needed to find ways to entice buyers or to keep production in line with demand.