The period from the mid-1960s to mid-70s was one of great cultural ferment. It was lively, exciting but also too confusing at times. On the one hand, there were the “small is beautiful advocates” and on the other was the “big’s the thing brigade”.
Let us look at how metaphors having to do with large things entered popular language and were meant to allure and entice. For instance, when Jumbo jets (which is what Boeing 747s were nicknamed) caught the public imagination, campaigns for various consumer products were pitched as “JUMBO” sales. Further on, marketers, going into overdrive, styled their pitch as “MEGA” (does one detect a connection, even if subconscious, here with megalomania?).
However that may have been, the prospect of whiling away time if there was nothing else to do, and to find something interesting or useful and worth picking up, all at one place, drew large crowds thanks to the “Jumbo” and “Mega” billing.
Around this time too came in a new experience in movie viewing: the 70 mm films that required cinemas to have considerably bigger screens than the ones used to show 35 mm films. And, sure enough, restaurateurs lost no time in dubbing larger versions of favourite snacks as “70 mm” this or that; it was as part of this trend it was that “70 mm” dosas made their appearance on the menu or bill of fare.