Bob Hoffman:

You would think a company that built its business on the promise of putting sophisticated data to work for advertisers would have the sense not to release numbers that are patently ridiculous.
 But time and again Facebook has undermined its credibility by making claims that are easily proven to be false, and then defended these claims with statements that are absurd.
 This week it was reported that Facebook was claiming to reach 41 million Americans between the ages of 18-24. If Facebook reached every American between 18 and 24 they’d still be 10 million short. There are only 31 million of them.