Touring the brewery, Hopkins saw bottles sterilised with live steam, water from 120-metre artesian wells and beer filtered through cellulose. He launched a 'Purity' campaign explaining the process step by step. Consumers thought Schlitz was the only truly pure beer, and within months it rose from fifth place to a top seller.

It means being the first to explain publicly a standard process that every competitor uses. Once you do, the public associates that process forever and exclusively with your brand. The host says this is exactly what Hopkins achieved with Schlitz's sterilisation and filtering, which every commercial brewery already did.

When Hopkins told the owners they needed to tell the public about their process, the master brewer asked why, since all commercial breweries did the same and it was a sector standard. Hopkins replied that nobody had ever told people, a remark that remained in advertising history.

In 1917, to stand out from competitors, Lucky Strike launched the slogan 'It's toasted'. In reality all tobacco for cigarettes in the United States was dried and toasted, but no producer had mentioned it. For decades consumers believed Lucky Strikes were gentler on the throat thanks to a secret process.

Hopkins pioneered traceable coupons and response codes in newspapers, and published slightly different ads in different cities to measure which headline or offer produced the most sales, an ancestor of modern digital habits. He also invented home samples and helped popularise the use of toothpaste, according to the host.

Hopkins held that advertising is not meant to entertain, make jokes or show abstract creativity, but only to sell; he championed scientific advertising. Drawing on his door-to-door sales days, he saw an ad as a seller in printed format. The host partly disagrees, noting the best ads also entertain.