I just noted that.
That is an excellent idea to raise money for the site! The sponsorship will also help get lesser-known simfile makers attention (if they are willing to invest the money to get on the board). Some people might say that this gives an advantage to the rich people out there, but if you are willing to spend a many hours of your time working on simfiles (when you could be doing other work, possibly paid labor), you probably wouldn't mind paying a small amount of money to have your simfiles get more attention.
P.S. Sorry, but I probably will not sponsor my simfiles.