Cover Letters and Cover Emails. What's it all about?

I often get asked about Cover Letters and Cover Emails and I get sent a lot of them to review. Recruiters and hiring managers get many many examples of good and bad, but ask yourself. What is the point of the Cover Letter/Email? It's to be used as a brief selling tool but mostly (90%) to make sure that your CV gets read and considered for the right role. What not to do! Don't write your life story! Don't make any mistakes! Simple is best. Recently on behalf of a friend I reviewed 100 CVs in one hour to create a shortlist for a job he had advertised. About 40 of them had cover emails so poor that it was obvious from even that much that could not do the job in hand. Which gives a 60% pass rate even before we get to the CV! What should it say? It should be as simple as possible and contain. Why you're getting in contact! Why you have the experience they're looking for! Call to action! Contact Details! All of this sounds obvious but if you can get this right, you're already ahead of 40% of the competition. Feel free to contact me for specific advice on this and other issues.