Children's Book Exchange

To do it or not? That is the question!
If you haven't encountered it before, it goes something like this:

" Dear XXXX,

This is a book exchange.  Please join us!  It's a fun and inexpensive way to stock your child's library with books. Send one book to the child listed as #1 below.  Then send a copy of this 6 friends.  Move my child's name to the #1 spot and list your child as #2 on your letter.  Be sure to include your child's age next to their name and address.

If you can't do this in approximately one week, please let me know.  It isn't fair to the children who have participated and are waiting for their own special books to arrive.  A manila envelope will mail the new book nicely. Another idea is to order a new book direction from a website like Amazon and have it shipped directly to the person you are giving your book to. 

Seldom does anyone drop out, because this is such a great deal -your child will receive 36 new books!
  Your child should receive their new books in about 2 weeks - that is, if you get your letters out right away.  Please don't be responsible for spoiling the fun and stopping the flow of book for children - please join us!

Also, please be sure to include a blank copy of this letter to each of your friends so they don't have to retype it.  (12 copies, on filled out by you, and a blank one for all six people.)"

This is actually the second time I received one of these letters. The first time was when my daughter was young, and I honestly did forget about responding to the person who sent it to me. But this second time, the person asked me in person, which makes me feel slightly more obligated. I do trust the person who asked me too.

So, should I or shouldn't I?!?
And if I do, anyone out there interested too?!?