In 2017, my granddaughters began selling me Girl Scout cookies, and my daughter raved about the cool new technology for selling it on the web. It is indeed cool, but it motivated me to document my own ancient Girl Scout cookie technology research.
In 1991, I had been doing research on "active email" -- essentially, email that includes computational elements that make the message potentially look or behave differently every time you read it. (Nowadays this kind of technology is making a comeback as "dynamic email" from both Google (AMP for EMail) and Microsoft (Actionable Messages).
The first practical use of this system was for selling Girl Scout cookies. (My daughters were 6, 7, and 9, all Girl Scouts, and I was a troop leader.) I sent the message to everyone at Bellcore's Morristown research site. When anyone read the message, a new window popped up on their screen: