ZenithOptimedia has released a list of the largest media companies around the world, ranked by media revenue, which it describes as “all revenues deriving from businesses that support advertising, not just the advertising revenue itself.” While only 4 online media owners made the top 30 list, it’s important to note – as the researchers do – that the figures pertain to the 2011 financial year, the most recent one that could be used for consistency’s sake. Since then, online advertising has been growing by leaps and bounds. And yet, even in 2011, one digital company ruled them all: Google.