Courier flights were real! I only did one of those, but a friend did a fair few to New York.
I remember the collective silence on allocation on arrival when the coach pulled up to the hotel or apartment and the air filled with hope or trepidation that your name would/wouldn’t be called out, depending upon the place!
Sometimes you’d call on these ads and they’d say that the flight had left that morning/holiday was sold out, but there was another holiday for three times the price they could offer you! One of my best deals was Australia for £200 going a week later - I assumed they were going to say the trip was unavailable when I called up, so was pleasantly surprised. There were three legs to the journey and I had the middle seat on the back row, but apart from that all good!