On Wall Street, the math geeks are known as quants. They're the ones who create sophisticated trading algorithms that can ingest vast amounts of market data and then form buy and sell decisions in milliseconds. Hammerbacher was a quant. After about 10 months, he got back in touch with Zuckerberg, who offered him the Facebook job in California. That's when Hammerbacher redirected his quant proclivities toward consumer technology. He became, as it were, a Want.