i tried that when it first came out, bottomline, it's now worth the money, is much better to hire a big facebook fanpage according to what you want to promote to do some postings for you
I never did try facebook ads before, It could be very expensive if you are not careful what you do, when you set up the payments options. I suggest you to sep up the payments options very low every time somebody clicks on your ad. I recommend you to go to youtube, and type facebook tutorials ads, there are tons of good tips of information on what to do and not to do. I hope that helps a little bit. All the best.
In my opinion is not worthed. The price is toooo high considering the chances to get any results. I agree with Rounderx.