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!"
The sales letter format should emphasize key points while maintaining simplicity. Do not repel the customers or clients. Have normal spacing between lines and the contents just right so that the reader does not feel over_burdened reading your letter. Get the reader to feel as if he is invaluable to you and your company. The pronoun "you" in place of "we" instills a sense of warmth in the reader, drawing them closer to your business.