In September 2005, Facebook opened to non-college students for the first time and allowed high school students to register for accounts. Loyal users were outraged, but the Facebook team felt that it was the right direction for the site. How could it produce evidence to justify its position?
In addition, Facebook had saturated the student population at nearly all of the colleges where it was available, but there were still some colleges where the product had never taken off. What distinguished these laggard networks from their more successful peers, and what could be done to stimulate their success?
When I interviewed at Facebook in February 2006, they were actively looking to answer these questions. I studied mathematics in college and had been working for a nearly a year on Wall Street, building models to forecast interest rates, price complex derivatives, and hedge pools of mortgages; I had some experience coding and a dismal GPA. Despite my potentially suboptimal background, Facebook made me an offer to join as a Research Scientist.
Around the same time, Facebook hired a Director of Reporting and Analytics. The director had far more experience in the problem domain than me; together with a third engineer, we set about building an infrastructure for data collection and storage that would allow us to answer these questions about our product.
Our first attempt at an offline repository of information involved a Python script for farming queries out to Facebook's ...