Using the Facebook platform for advertising can be extremely effective and profitable. Facebook Ads on the other hand have been lacklustre at best. They can be effective to drive activity to a Social campaign on Facebook, but are immensely less effective then google's ad products.
On the other hand, google knows it is likely just a matter of time before Facebook gets it right, and when they do they are one of the few companies who could complete at scale with google.
On the other hand, google knows it is likely just a matter of time before Facebook gets it right, and when they do they are one of the few companies who could complete at scale with google.