Circular letters are sent to a large number of people. They are unsolicited letters. They usually convey information about new product, a new service, a new set of terms and conditions, the opening of a new branch, change of address, telephone numbers, seasonal greetings, discounts, price revision etc. Today, circular letters are printed in computers and sent. They can even be e-mailed to customers. They are persuasive in style and are quite lengthy.