Subliminal messages in marketing are very real and can have great impact for better or for worse. Some movie theaters used to splice in a single frame of popcorn or other concessions into a movie so viewers might buy some for themselves. So subliminal you may not process it completely.
This ad from Reese Canada is not so subliminal. The reverse psychology employed leads us to an obvious CTA while actively discouraging it. It’s definitely sure to leave you wanting a peanut butter cup.