To think that Facebook and Pandora cannot monetize mobile will go down as one of the biggest bonehead misses of our time. Advertisers always have and always will go where the people go. They have absolutely no reason not to. In fact, if they do not, they risk almost certain death.
Social media heavyweights such as Facebook, Instagram and foursquare are addictive and useful to their members and increasingly and incredibly valuable to advertisers.
Take a subway train into Midtown Manhattan. Fire up foursquare on your smartphone. After your meal, massage or bookstore visit, try to argue with a straight face that these social media stars a.) cannot monetize mobile and b.) are nothing more than unsustainable flashes in the pan.