I remember Nov 2, 2002 It was Half Price Day sponsered by Kiss 103.5 Chicago. Admission was Half Off, Food and ALL MERCHANDISE HALF OFF> and the best part? ATTENDANCE WAS LESS THEN 200 people. it was so nice, we got to stay on raging bull for as many rides as long as no one entered your QUE. i mean yes it was only 20 degrees but it was so worth it. i never had to wait in line for ANY RIDE. I wish they would do it AGAIN!!!!!
Actually thats not the only reason, if that was the reason why would they have ever attempted to do it once?
Attendance was horrible for the last blast event, and while it was more then 200 people (I can only assume you were being sarcastic?) the park was empty that weekend, so yes they didnt make much money - Keep in mind even at 1/2 off they are still making money, plenty of it, but compared to any other day, it was completely horrible.
From what I remember though, they didnt announce last blast until a few weeks before it occured, so it was not advertised very well, nor did it give people much time to plan for it.