After reading excellent sample chapter from IPExpert's "IPv4/IPv6 Multicast Operation and Troubleshooting" book I decided to pre-order it. Today I got the pdf file and was very disappointed. The content is still great, but it can only be read on the PC or MAC - no iPad, Kindle or smartphone. Now, my commute is relatively long and I do most of my reading on the bus. Not be able to read documentation on mobile device is major problem for me. If greedy Hollywood studios found a way to provide their content on mobile platforms, so should IPExpert. Especially given the fact that INE provide PDF files DRM-free. This was my first and last purchase of IPExpert product.
Update: FileOpen released iPad/iPhone app, so now I can read that PDF on my iPad.