"The Grand Modern Ambitions"

"Of course, the very quality that made neon fixtures a poor choice for interior lighting made them perfect for signs, de Miranda notes. The first of the neon signs was switched on in 1912, advertising a barbershop on Paris's Boulevard Montmartre, and eventually they were adopted by cinemas and nightclubs. While Claude had a monopoly on neon lighting throughout the 1920s, the leaking of trade secrets and the expiration of a series of patents broke his hold on the rapidly expanding technology.
"In the following decades, neon's nonstop glow and vibrant colors turned ordinary buildings and surfaces into 24/7 billboards for businesses, large and small, that wanted to convey a sense of always being open."

Sarah Archer at The Atlantic calls neon "the Ultimate Symbol of the 20th Century."