this.
addition:
if you ever read the notes on that ponzi game (i did not like that "scheme" at all despite the fact that it explained what will happen if you play, there could have probably been a better demo use case) you'd know that it was also a test for automated mass transactions, and in the first days when it had to handle hundreds of inputs and outputs in very short time it demonstrated how quick the BC technology is and that it can be used for all kind of near real-time use-cases in a quite impressive manner.