Business was booming and the economy was pushing forward at rates unprecedented in the 1920s. Aptly named the Roaring 20s, big business became the norm, and chain stores (Woolworth's, United Cigar Stores) and mail order catalogs (L.L.Bean, Sears) became commonplace as well. Americans everywhere sought to fill any economic niche they could find, be it as file clerks, geneticists, short-order cooks, cosmeticians, columnists, or researchers. One might hire an efficiency expert at a time when the top dog sought to decrease overhead costs. Base pay was up thanks to the popularization of the assembly line and mandates from company unions.
Although there was traditionally a sense of kindness to strangers in the United States, profiteers began to exploit the idea that one could charge for anything done. Rather than going the extra mile, a service charge could be charged; otherwise, one would expect to serve themselves, developing the term self-service. White-collar workers took their briefcases to the finance company where they could make a few grand, some serious money back then. Several milliardaires were made: prosperous and wealthy entrepreneurs who put millionaires to shame and were later called a billionaires.
According to 20th Century Words by Ayto and English through the Ages by Brohaugh, some other words that came into the language or became more popular during this time are as follows:
Unfortunately, the speculation in the stock market led to a large recession (economic contraction), now known as the Great Depression. Finding themselves in the red, businessmen found themselves handed pink slips (notices of termination), and jobless/unemployment rates shot skyward. They thus become a bit skint (broke).