Privateer Press hit the proverbial nail on the head with their Full Metal Friday PDF releases. A few pages of pure crunch goodness followed up by a proper book release that also contains fluff and fiction.
It’s a little different with something like a digital codex, but in that situation I want an easy way to skip the story and get straight into the rules (without having to set my own bookmarks).
Jaded Gamercast 
Privateer Press hit the proverbial nail on the head with their Full Metal Friday PDF releases. A few pages of pure crunch goodness followed up by a proper book release that also contains fluff and fiction.
It’s a little different with something like a digital codex, but in that situation I want an easy way to skip the story and get straight into the rules (without having to set my own bookmarks).
Why? Because rules last an edition fluff lasts at least two editions! Due to retcons.
Short, provided there’s a paper book still kicking around. All the better if the short PDF/interactive iBook is included in with the paper copy.