Letter worked as a good promotional device for 'Pink': Big B

Megastar Amitabh Bachchan, who recently penned a letter to his granddaughters Navya Naveli Nanda and Aaradhya, says the note captured the essence of his film "Pink" and he feels it worked as a good promotional device for the movie.

In his letter, the 73-year-old attempted to impart valuable life lessons to his granddaughters.