Go to
www.entertainment.com and you'll see examples of the Entertainment Book. You can buy one for your local area or for major cities in the US. The book is full of discount coupons for local restaurants, fast food places, etc., as well as national coupons for car rentals, airline savings, and discounts on USF/IOA TICKETS (!). There are hotels all over the world where you can get an Entertainment rate of 50% off the hotel's rack rate, just for being an Entertainment member. (Hang on to your membership card.) The Portofino Bay Hotel and the Hard Rock Hotel are included. So are the WDW Swan and Dolphin. The lowest Entertainment rate at the HRH is $117.50 for a garden view room, so you'll recoup the cost of the book (about $20 plus shipping.) on that alone.
If you are an Entertainment member and want to join the Disney Club for the first time, you'll save 20% off the DC membership fee: $31.95 instead of $39.95. (Renewals and new memberships for former MKC members are $29.95.)