20 gifts certificates for a dollar sounds too good to be true and it is now, but in the late 1970s it was the perfect price point. And the perfect treat for the McDonald’s loving trick of treaters in your neighborhood. This was the era before self-serve and free refills, so each of these pieces of paper meant a icey cold coca-cola. When such treats were being handed out in my hometown, the news would spread fast and you best run to grab one before the family who was kind enough to carry them was emptied out.
I do not recall certificates for soft drinks being handed out, but I do remember ones for sundaes. Which I reckon must have been more valuable.