A good cover letter can make a strong, immediate impression. In many instances, it is the first contact you have with the employer and introduces you to them. The goal of your letter is to have them want to meet with you in an interview! The three elements of your job application package are: cover letter (may be in the body of the email), resume, and work samples (as attachments or PDFs).
JUST 30 SECONDS
Employers expect to gain a clear idea of who you are as a professional in the first 30 seconds it takes them to view your letter, resume, and work. After this they will take action - invite you for an interview or not, or at least read more and make a decision. Successful letters are a conversation with the employer where you give them enhanced information about the skills and projects that appear on your resume. The resume merely lists the skills whereas the letter is your chance to frame your experience in relationship to the job you are applying for. The letter should be a compelling narrative describing the important aspects of you, your work, and actual skills that matter to this particular employer. In the letter you need to answer the employer’s question “Why should I hire you?” or “What makes you different from the other applicants?”
“Employers expect to gain a clear idea about who you are as a professional in the first 30 seconds it takes them to view your letter, resume, and work.”