Facebook is work. Literally for me. I'm head of a web department that has an eMarketing dept.
One of our eMarketing services involves FB, FB ads, corporate pages, etc.
It has worked very well for some. Depends on what you do.

For an emergency service guy, adwords would probably be better. People search for it when they need it and if you are right there at the top your clicks will rise, and so will leads.

For a company that sells widgets that people only buy occasionally, FB (and FB ads) can be a VERY cost efficient way to build brand. Even if people don't click those little ads, when they want a widget there's a good chance your name will pop into their head. They've seen you on FB more than once and if the ads are done right, they will tend to give you a shot.
If you target only your geographic and client profile it can be done smartly for little cost. Some clients have tens of thousands of likes and see the return (and notice the un-trackable effects too). It can definitely work.

And then of course the active Business page (as Danny mentioned), groomed with extra software designed to improve the look of FB pages. Make a professional impression.

Enough about work, where's a good music thread..

I do not work here, but the benefits are still awesome
Make your sound your own!