Facebook has grown revenue per user by 500% since 2012. Television (advertising only) has grown 4%.

A single digital network now generates 40% of the revenue/user that the entire television industry does from advertising. This is why some people think that Facebook could eventually be worth $1t.

Why is this important? Networks like Facebook and Google are growing both their user base and revenue/user which should lead to a further explosion of total revenue. The user base for traditional media has matured which leaves revenue/user as the primary path for growing total revenue. Think higher advertising CPM $ and higher prices for cable tv.