Even as technology transformed the macroenvironment for advertising, its competitive environment is shifting almost as rapidly. Four Internet-era giants—Facebook, Amazon, Apple, and Google—once ruled separate domains but now are increasingly fighting for the same territory. Amazon started as a bookstore but now sells information for its Kindle e-reader, making it a competitor with Apple. Google created a social-networking service (Google1), and Facebook launched a search tool for its site. Some observers predict Google and Facebook will be players in the market for mobile devices, to drive more usage of their services.As they seek ever-larger shares of online activity, Facebook and these competitors rely on their customer data. Details about consumers and their behavior make advertising on Facebook valuable. Facebook has commissioned studies of the value of social marketing. In one case, it found that if Facebook users were fans of Starbucks (by “liking” the brand’s page and therefore
