Google never really was generous with its acquisitions: many of its most successful ones like Blogger, KeyHole (Earth), Where2 (Maps), Writely (Docs), Zenter (Presentations), Urchin (Analytics) and Android were for tiny dollar amounts, sub-$100M. And the really big ones - YouTube and DoubleClick, and to a lesser extent Metaweb - turned out to be worth way more than Google paid for them. The only big duds I can think of where Google paid a "generous" amount for something that didn't really make them a whole lot were Motorola, Andy Rubin's robot collection (Boston Dynamics etc.), and Skybox, and in all cases they managed to sell them off for decent amounts.