what to include in a cover letter

There are many job seekers who have that perfect CV that employers are always in search of. However when they think they have sent across perfect cover letter also and yet they do get rejected they are clueless what went wrong. It has been found in a survey that many job seekers who do not have a perfect cover letter are at a greater risk of getting eliminated. If the cover letters are half heartedly drafted or are replete with blunders, then it gets terrible.