100 Billion is a vast overstatement.
Phrased in terms of opportunity cost, it's appropriate, again if a bit high.
Media gets YUGE dollars from politics. That flow of money in politics is one of the biggest problems in the US.
Many want to fix it. That risk, in terms of the financial opportunity assessment under discussion right now, would reasonably ratchet that number down further.
> A staggering $24.1 billion of Google's $27.77 billion revenue for Q3 2018 was from advertising – roughly a 22% increase from $19.8 billion in Q3 2017.
source: https://www.investopedia.com/articles/investing/020515/busin...