The language used in the sales letter format should be simple, and suited to your trade. Complicated or complex writing leaves the reader confused and unlikely to read your letter or take action and buy. When a letter writer includes any bonuses, they should be supported with the word "free." For example: "FREE article submission with every SEO article!"
In reality, there are just some people who have developed this mania over grabbing hold of the most unique cover letter format they can find. They think that they will need all the research that can ensure their application letter achieves a desirable look. They feel that if it is not attractive or interesting enough, their cover letter format will end up being thrown in the trash bin.