In the first advertising campaigns the chocolates were depicted as the definitive token of affection, suggesting that there is no better – or more romantic – gift that a man can give his loved one. The adverts showed beautifully dressed women reading or writing letters telling of their romantic encounters over a box of Black Magic. The ‘letters’ campaign lasted well into the 1950s and established Black Magic as a brand known for its luxury and indulgence.

Info gleaned from http://www.nestle.co.uk