Just a note that you don't really have to get the 2005 book to get the 2004 book for free:
3. Entertainment will send a notification approximately one month prior to shipping your 2005 edition with the approximate ship date and when your credit card will be charged. The notification will also provide instructions for canceling the order. Most 2005 books will ship in August or September 2004.
4. If you do not cancel, Entertainment will automatically charge your credit card at the time your 2005 edition ships for the full retail amount of the edition - between $25 and $40 USD, plus shipping and handling is free (see entertainment.com for retail pricing by edition).
So if you cancel, you won't be charged. Or if you have the capability, you can use a one-time-use credit card number so they wouldn't be able to charge you if they wanted to.