If you donate $5,000 to a university they will invite you to one or two events a year where they show you the kind of research donations have been supporting, some students who received bursaries say how it let them buy books and focus on their studies, and the head of the university gives a speech about their vision for the future of the school. Important-sounding academics and administrators will circulate and talk to you as a peer.

Or, from a more cynical point of view, they make you feel important/distinguished/part of their community, in hopes of soliciting further donations in the future.

I assume, if you donate $50,000,000 they knock that up several notches.