Why did Katherine Fields write this letter?

Câu hỏi :

Question 98 - 100 refer to following paragraph:
Dear Readers,
This July, Horse and Rider will celebrate its 27th anniversary. Since its first issue was published in January of 1980, Horse and Rider has continued to bring its readers tasteful but entertaining articles covering everything about horses. To celebrate our anniversary, we are offering a special promotion to all our readers: a free three- month subscription. Plus, you will receive our special anniversary issue, which will be published at the end of July. This special issue will feature an article about Marjorie Clemmons, the Senior Editor and founder of Horse and Rider.
To be eligible for the special offer, just fill out the request form that is enclosed with this letter, and mail it to us by June 15th. As always, we welcome your questions and comments, so if you would like to be included in our From the Readers section, please visit our website www.horseandrider.com and submit your review electronically. We thank you for your continued support, which has helped us become the most popular horse magazine in the country.
Sincerely,
Katherine Fields
Public Relations Advisor
98. Why did Katherine Fields write this letter?