The True Gamification Of Advertising.
This multiple award-winning advertisement from the 1980s indicates that it's promoting Silk Cut cigarettes solely by use of packaging colours and the visual metaphor of slashed material.
It left the reader/viewer to work out the rest and thereby engaged them with a form of extrinsic gamification at a time before any marketers had heard that word.
That's quite a contrast with yesterday's unsubtle approach that scans as poorly as the ubiquitous obtrusive QR codes which are flavour of the month right now.
You can have engagement or you can have a shotgun wedding - we all know which is most likely to develop into a lengthy, meaningful relationship.