Contact is not enough. There's always contact in the box. Otherwise, there would be 10 penalty shots every game. And most of them at the end. If a ref doesn't be somewhat discerning, it becomes a joke.
That's why you are also seeing "Ajen Robbin dives to win the game for the Dutch". All over the internet.
Here's a Vine of the penalty. He barely gets his toe stepped on. If this is a penalty, then I take back my previous statement. There would be 20 pks a game. Not 10.
http://www.businessinsider.com/arjen-robben-dives-2014-6