FaceBook Ads, Given Away

FaceBook Ads, Given Away:

Facebook Advertising - strange and interesting beast.  I was given a 50 dollar credit for hitting 200 likes and it expires soon so I thought I’d try an add.  2 days have past and now I have 22 more likes.  That doesn’t seem to be worth 50 dollars at all, even supposing another 40 or so likes in the time the ad runs.  That says, I could have done it wrong.  Curious world, ads for self. Wonder if others have had any better luck?