Edit: Never mind, I found the following explaining their deal:
Under the new BCS arrangement Notre Dame will be guaranteed one of the at-large slots in a BCS bowl if it is ranked No. 8 or better in the final BCS Standings. It is also guaranteed annual payment for its participation in the BCS. In those seasons in which the Irish play in a BCS game, the school will receive $4.5 million (an amount equivalent that received by a conference that places a second team in a BCS bowl). In those seasons in which Notre Dame does not play in a BCS game, it is projected to be paid $1.3 million for its participation in the BCS arrangement.