this video I saw sometime ago, really explains alot....
Facebook Fraud - PlayIt.pk
And I've noticed it myself. And not just on facebook, even on orkut (years ago). I used to get membership requests on a car community where I was a mod from people in brazil. And upon closer inspection on their profiles, I realized they had no car photos or scraps or anything of that kind. Same thing I noticed on a page I started on FB, I was getting some random likes out of brazil. This is without advertising...
So my suggestion is make a website and use google ads to get people directed to your website and through that website get your customers connected to you through the facebook page.
Also, try newspaper ads or billboards, banners etc. these will be more effective in reaching people who don't use the internet regularly.