We all know Apple is one of the biggest companies around, but how big is just iTunes? Bigger than many famous, multinational corporations, as it turns out… and that’s without counting in iPhone, iPad and Mac sales. Asymco analyst and all-around numbersmith Horace Dediu decided to sit down and calculate how much iTunes was worth, and came up with a number of roughly $7 billion in revenue per quarter, with those numbers continuing to grow.