Continuously update your business' facebook page
A business page on facebook is practically useless if you don't continue to update it. And don't post just about promotions and new offers, but also about any relevant personal things as well.
For example, if your business is a band, don't just post upcoming shows. In fact, a photo of the band in their street clothes standing in front of the tour vehicle can often get more likes and comments than a live photo, and thusly get seen by more people.
Or if your business is a small one run by one person or a small group, such as an Etsy store, feel free to post about your pets or family to generate more of a personal connection. Or if your business page is for yourself as an author, or for your books, posting about your favorite books and writers, and not just your own books, helps a lot as well.
Change your page's banner every few weeks to keep people interested.
Come up with a new banner for the page every few weeks, or at least every month. This keeps people looking at the page, and gets them interested. It can even be a slight alteration to an old picture, as long as it is a new one being posted and not just an old banner being reinstated.
Attach a photo to every facebook post.
Posts get seen by more people when a photo is attached. If you don't have a brand new relevant photo, a photo that has already been used is far better than not having a photo at all. Some of your page's followers may not have seen that same photo on your page yet. A photo gets more people to like the post, and thusly gets more people to see it. A post with just text, no matter how intriguing and thought-provoking the text is, is uninteresting in the eyes of facebook users whose feeds are filled with updates from both pages and people.
Share the posts on your personal page.
Most businesses start off with friends and family as clients. Share your business page's posts on your personal page as well, to encourage any friends who have not liked your business page to start following it, or at least reply to the posts. Any exposure is good exposure, even to your friends and family.
Interact with people.
There are two ways that any successful facebook page can interact with followers, and keep the interaction going.
First, your posts should contain a question. Not only is facebook more likely to show each person more posts that have questions, but it gets a conversation started with anyone who answers the question. The more people who are encouraged to comment, the more additional people see the post.
Second, anyone who comments should be met with a reply from you, the page. Not only does the fact that you reply generate a personal connection of some sort, but it encourages the followers to keep looking at your page.
Hosting contests can get your followers involved in your page. Give away a free CD to whoever comes up with the best design for your next album cover, or leaves the best comment on your new music video. Give someone a free chiropractic session if they design the best new banner for your page. A free drink at your bar can be a prize for coming up with the best song suggestions for karaoke night. It can even be as simple as getting a sticker for answering trivia questions about your business.