I've been doing lots of tests (different creatives, different ad fomats, different targeting (wide vs narrow)) to properly elimintate Facebook from reasonable marketing, but I just found a format that really works and was giving me a 2.9% click thru rate with a $0,06 CPC. Wonderful. Clearly it was too efficient because FB told me that it violated their advertiser terms because there was too much text in the picture.
So, it worked...for a bit.
Then FB nailed down on one of the few ad's I've run that was delivering ROI.