I suspect that once they tally up the challenge donations it will be twice that amount. One challenge alone was 50k. I believe its based on the number of people joining in on the challenge, not necessarily the amount. So any small donation will help initiate the challenge.
Football ended up way ahead of the others with around 250 donors and a total of $84. I think they marketed a bit differently this year, focusing on younger alum and with lower challenge levels.