Greg,
The unfortunate part of this business for on-air jocks like yourself....is that you will work for what the GM thinks you are worth......nothing more and hopefully nothing less.
The GM bases that judgment on your ability to get ratings, your committment to show prep, your creativity, your willingness to be out front as much as possible, your attitude, your desire to pick up the slack when help is needed, your refusal to talk negative about the company and other people around the office, his perception of your weaknesses (poor negotiating skills, needing a job, etc. etc), connect with your listeners, build local advertiser loyalty with you and your show, establish leadership and build peer respect.
You work on and perfect these elements and you will strengthen your perceived worth and increase your compensation capability.