Good article. I think rule 4 spells it our very clearly for those doing giveaways. My ebook isn't really a giveaway it's an incentive for liking my page and was only sent to my newsletter subscribers. Same as an incentive I give to newsletter subscribers.
"Rule 4: You must not condition registration or entry upon the user taking any action using any Facebook features or functionality other than liking a Page, checking in to a Place, or connecting to your app. For example, you must not condition registration or entry upon the user liking a Wall post, or commenting or uploading a photo on a Wall.
You can have someone �like� your page or check in to a location to enter your promotion, but that�s it. You can�t force them to like a wall post, post a newsfeed, invite friends, update their status, etc...."