Zuckerberg, like Google's founders, understood advertising's potential to degrade his product; he had the technologist's wariness of advertising and its tendency to ruin websites. As with Larry Page, so with Mark Zuckerberg, the Holy Grail was advertising that people actually wanted to see; Facebook figured that nanotargeting could make that happen. Until then, Zuckerberg would remain manifestly averse to anything that might interrupt the experience of his users. When, early on, Sprite offered $1 million to turn the site green for a day, he didn't even consider it. As he once put it: "I don't hate all advertising. I just hate advertising that stinks."

Tim Wu, The Attention Merchants, loc. 1000