The ticket office has "windows" for purchasing seats. The "windows" open on different days. Windows for very generous donors open earlier than windows for mere generous donors, and windows for generous donors open earlier than windows for those who make respectable donations, etc., until you get to non-donors. There are plenty of seats available for most games (USC was the only one this year tight on available seats at the non-donor level that I saw). I don't have a problem with giving donors something in return for their donations.