There are a lot of ways to earn money on FB. I tried Approfit Ad Network, they pay 5-10 cents per click. There is quite simle registration,has anyone tried it already?
Well facebook is good but you know market is common and majority of people are normal social visiting free people, so i guess it is not that good.Like in google some one is searchin hositng, your ad would appear through google keyword.That shows you can target your market in facebook you cannot target your market.
the best way to make money is: first generate your own website. Work on your website marketing to increase your traffic Then you will get the money better than FB apps Good Luck
I still doubt whether the ads from facebook can make money, but many of the publishers utilize networking site facebook for increase their page rank sites