Charging the applicant for a monthly premium listing service does nothing to help companies find good employees, though I think a small change could make it beneficial to both parties.
Offer "premium" application placement on a per application basis instead of monthly. This would provide a signal to the employer that the applicant is particularly interested in this listing and not just spamming resumes.
It would provide a similar signal to a customized cover letter, but the employer can see the signal without the necessary investment of time to read a cover letter.
