#9. Google Buys DoubleClick
Google (GOOG) knew that its core business of online advertising was a big deal, and looked to consolidate power in 2007 with the purchase of DoubleClick. In fact, Microsoft (MSFT) tried to complain about antitrust issues because of how dominant the internet stocks were collectively at the time.
But the deal went through, and the rest is history. Google’s total advertising revenue has tripled since the purchase, from $16.4 billion in 2007 to $50.5 billion last year.