Flipkart Minutes took to print on 17 November to roll out an ad about its '10 minutes' delivery option.
The innovation which ran in The Times of India and Hindustan Times in New Delhi, Mumbai and Bengaluru, used hydro-chromic ink which meant that users needed to rub water to reveal the hidden message.
Conceptualised by Leo Burnett, the innovation came with a headline 'don't cry over spilt milk'. When one applied water over the 'milk', the hidden messages appeared.