Zeynep Tufecki has written this NYT oped. A snippet:

How did Mr. Obama win? The message and the candidate matter, of course; it’s easier to persuade voters if your policies are more popular and your candidate more appealing. But a modern winning campaign requires more. As Mr. Messina explained, his campaign made an “unparalleled” $100 million investment in technology, demanded “data on everything,” “measured everything” and ran 66,000 computer simulations every day. In contrast, Mitt Romney’s campaign’s data operations were lagging, buggy and nowhere as sophisticated. A senior Romney aide described the shock he experienced in seeing the Obama campaign turn out “voters they never even knew existed.” And that kind of ability matters: while Mr. Obama did win decisively, the size of his lead in four states that determined the outcome, Florida, Ohio, Virginia and Colorado, was about 400,000 votes — or about 1.2 percent of the eligible voters.