Sell your track record and relevant accomplishments (i.e., your ability to deliver results) to show the interviewer what you're capable of doing for the organization. (theladders.com)
But couch it in terms of what you want to do for an organization not what you are looking to gain. (jobcluster.com)
In a circulation clerk cover letter, you should focus on what you can do for the organization through effective play of words. (coverlettersandresume.com)