A Gopher database lives forever unless someone kills it. Applicants who were just out of school three years ago and therefore not very marketable to a contingency based recruiter can be very valuable after those three years. Staying in touch with them can be very profitable. Keep your file current with current phone numbers and addresses; don't lose track of people just because they moved or changed phone numbers. Send letters with 'return address requested' so the post office gives you new addresses.