My favorite promotion of this style was with United Airlines in the early 1980's. United expanded service to include all 50 states (including one round trip a day from New Castle airport outside Wilmington DE to Chicago: an airport that today does not have commercial service). To publicize that expansion, United offered a challenge. Anyone who could fly United to or from an airport in all 50 states in 50 days or less would win unlimited first class travel on United for one year.
United expected at most three or four people to pull off this stunt. The final count: 60. They were stunned. One issue they did not consider was kind of a loophole. Back then it was possible to purchase a discount air pass in Hawaii that permitted travel on the mainland for a specified duration. Contestants who figured that out, flew to Hawaii, bought the pass, then headed back to the 48-states and had at it for a couple of weeks. Other tricks included round trips that arrived at JFK and left from EWR (NY and NJ), and taking four and five flight cross-country trips that connected here, there, and everywhere. I think the planning for that must have been quite a chore. That was way, way pre-internet. I bet there were some well-used copies of the OAG along for the rides.
Of the sixty people who completed the challenge, some did it to save on business travel for the year (a frequent flyer could save tens of thousands of dollars), others just as a lark. Sadly, I was not among the group of 60 (vacation time and funding were issues). With Delaware not hosting any commercial air service, a "50 in 50" challenge could not be held today. Maybe "49 in 49?"
