I have been running a Facebook ad campaign for 5 days. The micro-targeting that Facebook gives me has resulted in a large number of click-throughs at a low cost but no conversions. I had stared at the landing page for hours but could not see anything "wrong" with it. I then asked my wife (who is always willing to offer criticism) to look at it.
She is a member of my target audience (middle class mothers) and she did not understand the offer at all. We rewrote it together and overnight I had 7 conversions. The moral of this story is to get a member of your target audience to review your landing page because they will see it differently from you.