Most of them are pathetic. The skill of drafting sales words on a letter is an integral part of the sales process, because it creates an impression of you and your company when the customer or prospect reads it. Here's how it works. If you write a great letter, they think you're great. If you write a creative letter, they think you're creative.
Some salespeople have a hard time coming up with the appropriate words.
Not because they can't write, but because they don't know the rules of writing. You can even use a headline above the body of text. Use short paragraphs. Edit, edit, edit. Take out every word not integral to the purpose or objective of the communication.