They can be job seekers' ticket to land a job. It will dramatically increase their chances of getting interviewed. With the correct format, their efforts will eventually pay off once they have opted for a job interview. However, one of the biggest mistakes of creating one is that people tend to copy on the Internet. Some of them are looking into others' letters on the Internet and make it their own. With a little bit of editing, they can be able to pass it. Companies nowadays are aware of that scheme, so people should take effort in deciding whether they will copy on the Internet or they will create their own, unique and compelling letter.
If you want results for your efforts, then what you really need is to understand the most critical aspects of the cover letter. The format is just one aspect. There are more details that you have to take into account. The content is the most essential point you have to bank upon. You might have a very crisp paper with nice format in it but it will not be helpful if you do not indicate the skills and credentials required for a certain job position. Of course, you need to possess the same essential skills, traits and knowledge. Thus, you must evaluate first your qualifications before aiming for the brightest cover letter format.