I was a travel agent back in the 70s when they first got the 707s. One friday afternoon we got a phone call asking if anyone wanted to go to Athens on Sunday. Just the flight there and back. I think it had been scheduled for a Comet 4B but then they got the 707s with more seats and had spare seats! Saw some friends on sunday evening and they were a bit surprised when I said I'd been to Athens and back for the day!