Because we'd read it and instantly forget it. He's doing deep reinforcement by setting up a puzzle that intrigues people enough to try to solve. Then, when they've gotten as far as they can, he adds information to clarify some of it. The result, of getting the reward of answers after searching, drives the information deeper into memory. Also, the excitement of group solutions encourages people to pull people into the game. That spreads the information to people who would not hear it otherwise.
Four years between presidential elections can mean a lot of people drifting away. This keeps them attached and active, ready to be drafted into even more active endeavors.
By the way, new historical video of Henry Livingston's Revolutionary War diary during invasion of Canada, done to Hudson River School images and period music.
INDEED.