Goodreads has gotten into the daily ebook deal notification business. It looks like they'll notify you if a book on your Want To Read shelf has a price drop and/or they'll send you a daily email for any or all of the following genres:
- Bestsellers
- Romance
- Mystery & Thrillers
- Fantasy & Sci-fi
with more genres to come. Right now it's for US members only, and you can select to watch prices at Kindle Store, Apple iBooks, B&N, Google Play and/or Kobo.