How Important Are Cover Letters?

So how important are cover letters? Not very.

Here’s why: If I have your cover letter, I also have your resume. If the resume is well crafted, I should be able to glean immediately your area of expertise, your schools/level/training, typical clients, relevant experience, and accolades. I also should be able to tell from your resume how you are right for the job and this move makes sense. Your cover letter doesn’t need to retread all that.
 
A well-written and short cover letter can be helpful in 3 scenarios, however:

1. The cover letter explains how we know each other and identifies an important mutual contact. This connection will make me pay more attention to your resume (or at least open it).
2. The cover letter includes relevant information that doesn’t fit well in a resume. You could explain how you took technical classes equivalent to a CS degree, or how you built successful apps, for example.
3. The cover letter explains a complicated work history showing how all the themes in your life lead to the job at hand.

If you are sending your resume via email, you have to write something anyway. A good cover letter addressing the scenarios above can make an impact, but spend most of your time on crafting your resume.