You're worth 36c a month to Facebook

Surely there has to be a math error here right?
- http://www.saurabhnanda.com/2012/02/advertising-as-business-model.html

Facebook gets an average of 13 pageviews per-user per-day.
Each user visits Facebook an average of 40 times per-month.

This would mean:
a minimum of approx 440 billion pageviews (!) in Dec-2011 [2]
a maximum CPM of 60 cents per thousand page views [3]

Or = 36 cents per-active user, per-month????????