Yet patent medicine's most important influence was not on medicine but on advertising. As the industry grew, its pressing advertising needs drew many of the nation's most creative and talented copywriters, who would come up with some of modern advertising's most important techniques. It was also through the sale of patent medicine that advertising first proved conclusively its real utility, as a kind of alchemy, an apparently magical means of transforming basically useless substances into commercial gold.

Tim Wu, The Attention Merchants, loc. 88