"Trump hasn't been shy in boasting about his ability to drive media coverage, often tweeting about how his frequent appearances boost TV ratings, while benefiting from unfiltered livestreams of his campaign events.

"I've spent zero on advertising because you and Fox and all of the others — I won't mention names, but every other network, I mean they cover me a lot, to put it mildly," he told Fox News host Neil Cavuto in October. "And in covering me, it's almost like if I put ads in on top of the program, it would be too much. It would be too much Trump.""

And Trump got billions of dollars of free advertising.