Because there is no production capacity shortage. There is an artificial shortage of liquidity, mostly imposed on the poor. The financial sector exists to provide more liquidity, often by creating money out of thin air; but they only allocate to their friends, while trying to hurt their enemies (the poor) with austerity.

Anyway, the spending on ad revenue indicates that there are more people trying to sell than there are actually producing what they sell. Selling has become an industry unto itself. It doesn't really matter what they sell, they are salesmen. They try to sell everything, anything. In prison, I watched a guy collect a bunch of bread slices, to trade them. "Look at the big bread pimp!", another guy said.