The 18-34 demographic has been important to the advertising business since at least 1922, according to a 2002 article in the Chicago Tribune. The idea of targeting younger people is based on some evidence, but mostly on the belief, that getting a person to favor your brand early and therefore over a longer time span gets you a higher return on your ad spend.
Nielsen: 18-34 Undergoing Rapid Changes Since 2017
![Nielsen: 18-34 Undergoing Rapid Changes Since 2017](/media/articles/240509-MV-ITOROI-post-cover-image.jpg.550x380_q85_box-22%2C0%2C444%2C293_crop.jpg.webp)