He is paid a base salary from the University that is in line with a tenured professor. In addition to that, he is paid handsomely for his coaches show, he gets a slice of the apparel deal, and of course there is an endowment for his position as head coach, that contributes to his pay. These payments outside of his actual salary make up the majority of his total compensation, and are rarely reported to the public. It is for that reason that these lists of coaches pay are a joke when it comes to private institutions. If is safe to say that Brian Kelly is among the higher paid coaches in college football.
BTW, can anyone really be fooled by the reports of BK being paid in the 1.6 to 1.8 mil range when they just hired a coordinator that almost certainly is making much more than that?