I owned my own business for 14 years and used email, facebook posts, and blogs as my main advertising. My email consistently earned a higher than normal open rate because my customers found them to be informative and enjoyable. I was a Realtor in the 80's and am familiar with the basic letter realtors send. I would like to include a little personal information about you or members of your firm as well as a few statistics. If you have a customer willing to write something in your letter it would be ideal.