That's probably it, but I added up all the file donations, and it went to $445.89. Considering how long the file sponsoring has been going on, I don't think it's a very effective system. I think Into The Inferno ruined what this was originally supposed to be, which was probably an alternate form of rating good simfiles with money.
EDIT: Wait, you can sponsor you own files? WTF is that?
Then again, why would someone want to buy their simfile's popularity? Hiryuu, OMGINEEDTOPAYBILLS, inthegroove, and aquiball2 puzzle me.
EDIT2: I'll bet they'd make more money with a simple PayPal Donate button on their sidebar.