T-Shirts at Fundraising Events

Recently Purdue had its annual PUDM, and over a $1 million was raised for the Riley Hospital for Children. That is an incredible achievement! 

However I am skeptical of some parts of PUDM. 

One initial reason is that their website advertises that a reason to participate in PUDM is to "build a résumé." Is that really a respectable reason to participate in a charity event? The results are the same regardless of the motive I guess, but really? 

In addition, the ($250+) sign up fees which participants in the dance marathon pay. Part of this (I assume) is used for facility costs, which is an understandable cost in order to host such a large event. Another part of it (I assume) is used for the t-shirts which participants receive and wear during the dance marathon. But why does their need to be a dance marathon? Why do the participants need t-shirts? The major benefit of t-shirts which comes to mind is the advertising of PUDM to the Purdue community. T-shirts help get the word out, and might inspire some people who are interested in getting an awesome t-shirt too (again not the best reason, but...). I'd also be very curious to see how much of the money raised for PUDM is actually raised during the dance marathon itself. Would PUDM raise any less money if the dance marathon was 12 hours instead of 18? Or if everyone was just sitting in a gym calling supplied phone numbers on their cell phones? (Phone calls are already traditionally made during the dance marathon, asking for funds).

It is commonplace for participants in fundraising events to walk away with t-shirts. But how much would we raise if the t-shirts (and other possibly superfluous items) did not need to be paid for?