Craig Montuori, Caltech class of 2008, knows he should devote every waking moment to the startup he cofounded last year. Yet he compulsively spends two or three hours a day on Quora, a question-and-answer website he describes as "very addictive."
Michael Wolfe, an entrepreneur deep into his fourth startup, also can't help himself. If Quora sits open in his browser, he feels its tug. Someone will pose a question in one of his areas of expertise—the Silicon Valley startup scene, for example, or venture capital—and "it's Pavlovian," he says: He feels compelled to respond immediately and with enough authority that votes from fellow users push his answer to the top. Wolfe has forced himself to stop using the site at work. "If I didn't limit myself, I'd check Quora relentlessly," he says.