Even if your goal is to generate leads from Facebook, you don't want to make every post a photo of an ebook with accompanying copy that says "Download this ebook here: http://link.com" Instead, switch up lead-gen posts and fluffy, engagement-only posts -- you'll get more people interacting with you (and that means you'll have a better chance of being shown in the News Feed later on) and grow your Fan base. That way, when you do have lead-gen content, you'll have a much bigger audience available to click on your links.
Bonus tip: For all content that has links in it, be sure to place the link before the end of the fifth line of text -- that's where it will truncate and include a "see more" tag. That way, your Fans don't have to click "see more" to access your call-to-action.