When you do good work, word gets around.

Ms. Gregor, I would dare to imagine you scored rather high marks within your study of residential real estate and selling, to which I am most grateful. I say this, for I am a beneficiary of your skills, savvy know how, and intellect. Your professionalism is top notch, accented by a genuine caring, friendly manner. I have spoken hightly of you to others when such opportunities present themselves. I do so without any incentives or expectations in return. When you do good work, word gets around. It was by word of mouth (K. Smith) that you were recommended to me to consult with. Her praises of you, expressed with great enthusiasm, sold me on you. Now, I find myself recommending you to others in a similar enthusiastic style.
I hope that you will have phenomenal success throughout the years.