All businesses that operate within a local market can benefit from a properly-maintained Facebook page.
Some quick tips:
1. Don't scream "THIS IS WHAT I DO!" in every post. Actually...don't do it in 99.9% of your posts. That's what the info tab is for. If someone's connected to you or your page, then he/she knows what you do. Facebook is for conversations...start having them and stop selling. Using Facebook as an advertising platform is the #1 reason I hear "We tried it and Facebook just doesn't work for us".
2. Promotions are a good start. They're definitely not the end, though. They're a quick way to get people to connect with you, but it's the equivalent of filling up candy jars at insurance agents' offices and hoping that will persuade someone to refer you a water damage job. Use them as a means of engaging your connections into conversations and don't use them as a crutch.
3. Learn when to post updates. 2am is not the right time. 7pm on Tuesday, though?! Prime.
4. Don't be a robot. When's the last time anyone here called a 800 number and enjoyed talking to an automated answering system? I'd suspect never. The people connected to you and/or your business don't like it either. Be human. Do you like coffee? Post about coffee. Did you have something weird happen overnight? Write it down. And post a picture.
5. Get proactive. No, I don't mean this:
www.getproactive.com. I mean initiate conversation on something your "fans" post. Commenting on their posts is the easiest way to get that conversation going.
These are some of the basics of Social Media Marketing and should get you off on the right foot!
Hope this helps!