Tawny,
As you think about an alumni website for your school, consider what would draw your graduates. What things could you include that would provide that "buy-in"?
You might consider components that alumni are looking for like a Job Board, an Alumni Directory (to connect with old classmates), or other helpful information they might be interested in - Career Services, Loan Info, Continuing Education. You may also want to consider some things that would, literally, force them to your site like Transcript Request Forms or Grad Surveys.
June Gudeman