Don't write well. Use words that sell.
Some words are proven to persuade. A “swipe file” is a collection of presentations, headlines, websites, etc that have been used by others and have proven persuasive value. Copy them but not blindly. Make sure that they can be transplanted to your use.
How To Persuade
When you write, ask these questions:
Who is my target audience?
Why would they want what I recommend?
What are the strengths of the opposing ideas?
How are my ideas better?
And, when you want to persuade, focus on the benefits of the action you recommend. Talk about the results.
A lot of people try to explain how great their product is - without telling about what it can do for their customers. Make the product front and center.