"Promotions deprive you of your self consciousness. It does not give you a chance to be so ... much as we may like to be obsessed with the temperament. It is a necessity now, a must, a budgeted must and so we do it," the 72-year-old posted on his official blog srbachchan.tumblr.com.
He further added: "I wonder often who really is the true benefactor of these promotions ... for if the film is weak and disliked by the audience, surely any amount of glorification pre or post would not ever enhance the box office. Would it?"
Nevertheless, he still does everything to glorify his forthcoming films.
"Here we are ... artists of a different generation a different league, a different age, succumbing to the lured charm of a million interviews, appearances and presence on reality shows, trying as best we could what may be the right equation to get everyone in the entire universe to come and see our film," he wrote.
Amitabh, who will also be seen in films like "Wazir" and "Piku" this year, says there were hardly any promotions required earlier.
"My colleagues of yore have shown no interest in these shenanigans, and they may be right. It was never needed in their times and so why now ... but ... I guess my category has been through a drastic change and therefore it compels me to do what I never did before and do what I am required to do now," he shared.
"So ... apart from some of these appearances on shows and ceremonies, there is this trip to out stations ... Ahmedabad, Pune, Kolkata, Delhi, Bangalore all in the realm of 'perhaps'," he added.
Directed by R. Balki, "Shamitabh" will release Feb 6.