This is a stupid question but it has to be asked. Does your sales letter create as many sales as you would like. What proportion of them respond to your advert? What is just as important, how many of those that responded actually purchased your product? How can you improve the response rate? How many new email addresses did you capture? Do you have an 'opt in' strategy so that you can mail them later with more offers without being accused of spamming? Let us look at the sales letter first. .