Here's how many people the Russians could have reached by spending $100,000 on Facebook ads
https://www.cnbc.com/2017/09/29/russian-facebook-ads-how-many-people-could-you-reach-with-100000.html
With a budget of $100,000, you can run an effective campaign on Facebook no matter if your goals are to reach a mass audience or a smaller, specific group of people according to media buyers.
Facebook said in early September Russian operatives spent $100,000 on ads with "divisive messages," which seemed to be aimed at influencing voters in the U.S. presidential election. Though the ads never directly campaigned for President Donald Trump, Facebook said they mentioned hot-button topics. A recent story by Politico said some ads promoted alternative candidates like Jill Stein and Bernie Sanders, as well as criticized Hillary Clinton and "praised" Trump. A source also told CNBC that some of the ads mentioned Black Lives Matter.