EON Magazine, the official magazine of EVE Online. The offer also extends to MMM's other EVE publications: The ISK guide, EVE Strategic Maps and a poster pack. These are all paper-based products that will have to be sent via post, and unfortunately the price reduction doesn't extend to postage. For details on how to get in on this deal, head over to the official EON blog.
EON is published quarterly and has recently reaching its 25th issue. The magazine has a professional quality to it, and interestingly the only advertisements you'll see in it are for in-game EVE Online corporations and services. The Industrial Sized Knowledgebase is a professionally laid out print copy of the most comprehensive guide to EVE ever released. A basic version is available for free as a PDF, and the purchased product is an extended reproduction delivered as a colossal ring-bound reference manual. EVE Strategic Maps is an accurate map of New Eden ready to be filled with post-it notes on big finds, wars and travel routes.