No,

, I am not making it up. I am just a pretty curious person. Harper Collins outsources to Overdrive.
http://www.overdrive.com/news/pr/11052001.asp. Penguin uses Lightning source (and I believe Kensington which is distributed by Penguin also uses it).
http://news.com.com/2110-1023-272025.html.
Lightning Source also does Simon & Schuster:
http://www.btinternet.com/~akme/lightng1.html
and I believe Random House but am not completely sure on that.