Advertising and Association
From Buyology: Truth and Lies About Why We Buy:
In 1997, in preparation for the ban on tobacco advertising that was about to come into place in the United Kingdom, Silk Cut, a popular British tobacco brand, began to position its logo against a background of purple silk in every ad that it ran. It didn't take long for consumers to associate this plain swath of purpose silk with the Silk Cut logo, and eventually with the brand itself. So when the advertising ban came into effect and the logo was no longer permitted on ads or billboards, the company simply created highway billboards that didn't say a word about silk cut or cigarettes but merely showcased logo-free swaths of purple silk. And guess what? Shortly after, a research study revealed that an astonishing 98% of consumers identified those billboards as having something to do with Silk Cut, although most were unable to say exactly why.
And the real kicker? This type of advertising is actually more effective.