The frequent flier program

I have mileage point of frequent filier program UnitedAirline provides. But the expiration date of it is October 30th 2006. When I earn miles by traveling with airplane or buying something in online-shops, or eating participating restaurant. expiration date of that will be extended for 3 years. And I bought a book. The book is a English book that is novel for childern. I'll get 3 points added to my frequent filer account after 3 months, and expiration date will be extended.