So I just got another email today for $5 off of titles on my wishlist.
The interesting thing is that, so far as I remember, this is the first time I've gotten an offer like this on books from anyone other than Penguin-Random House. This offer is on two books from Simon & Schuster.
The funny thing is that one of the books is currently on sale for $4.49, so I ended up getting it for free (well, they charged sales tax). That was a no-brainer.
Anyway, apparently Amazon is expanding the experiment to other publishers.