We contact our grads with a newsletter format monthly (this seems to work best) we have found that by asking our grads to participate in submitting articles for the newsletter (whether it is work related or product related) it keeps the grads keep coming back.
We also have an incentive referral program for grads. We encourage our grads to participate as a teacher's aid, which in some ways gives them a job right out of school and keeps them attached to the college.
Student surveys can be a bit tricky to get participation, so once again we offer bookstore incentives etc.
It does seem to be a full time job to manage the survey data - So we send them out only as needed.
Thanks Susan. Cheers. Kate