Packt now has 1,000 titles! Packt's royalties sharing model contributes a percentage of book royalties back to open source projects, and they've now exceeded £300,000 in contributions. (Packt is a UK-based company.) To celebrate their 1,000th title they are offering one free ebook to anyone who already has or creates a new account at PacktPub.com. This offer, as I understand it, lasts until the end of September, 2012.
Over the years, I've published seven books and a number of articles with Packt. In fact, my author ID on their website is '4'. It's been great to see a startup thrive in an industry long dominated by a select few giants. Packt has also been a huge force in publishing Drupal books. While big companies like O'Reilly have a few Drupal titles, Packt has around 40.
EDIT: Originally I said three free ebooks. This was incorrect. It's only one.