Twitter and Facebook are committing stock fraud and charging for ads to “people” that do not exist. The numbers they claim are way to high. They expect you to believe that more then a third of the worlds population has A) a computer B) signed up for Facebook and Twitter and C) are active accounts and not “bots” that the companies are using to commit fraud.
Google and others regularly commit ad fraud and have been caught. They then give back some (not all) of the stolen money.
https://www.cnbc.com/2017/07/21/google-oath-others-ad-fraud-widespread-problem.html
Google search results: As of the second quarter of 2018, Facebook had 2.23 billion monthly active users.
335 million for Twitter.