Simply put: We follow where growing companies are looking for talent. That's our indicator.
Banks, hedge funds and other parts of the financial sector use a hell of a lot of fancy tech (they're the first "big data" after all), and there's a lot of expertise that's been locked up there for too long.
When I left finance (4.5 years, 4 years ago... hells yeah) I had all sorts of engineering skills, but knew nothing of the companies, how to evaluate employers, or what exact tools were most in demand or growing.
Helping people answer those questions more quickly than I could is our mission.