With the Yahoo deal, Verizon will pass Google and Facebook to become the biggest web network
You might not think of Verizon as a web powerhouse, but with the purchase of Yahoo, it has the potential to own the biggest audience of online users in the United States.
This chart from Statista shows ComScore's June 2016 measurements of visitors to the most popular networks of web properties in the United States. Yahoo has long been number three behind Google and Facebook, and now has about 206 million unique visitors. Verizon also owns AOL's network of sites, including properties like the Huffington Post, Engadget, and TechCrunch, which account for another 153.6 million.
There's almost certainly overlap between the two audiences, so the total will be somewhat less than the 359.4 million you'd get if you simply add the two audiences together. But the total could certainly be bigger than Google's monthly US traffic of 241.9 million.