Should also check in "who links to us" db to see if the link is also included.  Can also check the # of visitors sent to us here.  If less then specified number, disallow, and tell link too new, or link not prominent enough.  Must have sent users to us, or at least been on the page for 30 days or more.?

This can be a great feature for free postings to Avjobs Employer System, and/or free membership to applicant system?