I am writing this letter to show my sincere appreciation and to compliment you on how you run your business.  In a word, you are a master!  Every time I call upon your assistance I am in awe of how fast, proficient and complete your results come through.  You should write your own book on customer service, since I believe you have mastered the delivery of outstanding service.  Yes, many books have been written on the subject but you have achieved greatness in providing excellent service delivery.