Run Facebook-Only Campaigns

Want to give your audience a good reason to like your page? Offer them things they can only get through Facebook. For example, if you're running an e-commerce store, share discount codes through your fan page that you don't offer anywhere elseā€”in effect, offering sales exclusively to your Facebook fans. If you're running a blog or other type of site where you're generating revenue from advertising, give Facebook fans advance notice to better content. Better yet, create content that only they have access to.

(MLA 8th Edition)