Not sure if these are one of the permanently free eBooks or not, but it seems they actually sell the Best in Travel in hardcopy for actual cash (~12 bucks off Amazon), so the ebook version must worth something.
Lonely Planet's Best in Travel 2012 free on iTunes
http://itunes.apple.com/au/book/best-in-travel-2012/id439608…
Hard copy price reference.
http://shop.lonelyplanet.com/world/lonely-planets-best-in-tr…
http://www.amazon.com/Lonely-Planet-Planets-General-Referenc…
Lonely Planet's Recession-busting Britain: Best Free Experiences
http://itunes.apple.com/au/book/recession-busting-britain/id…
https://play.google.com/store/books/details/Lonely_Planet_Re….
http://ebookstore.sony.com/ebook/lonely-planet/recession-bus…
http://www.amazon.com/Recession-busting-Britain-Experiences-…
Woah, a sea of unpublished red. What happened?