Any organization at scale just needs a lot of people to deal with keeping the wheels on the bus. There are Computer Science problems that need to be solved every day to keep the site running, a team to handle billing problems, fraudulent payments, a sales team to go after corporate customers, now you have so many people in the office that you need inhouse HR... oh look, now you need a recruiter to start keeping all these candidates coming in the door... now you need accountants to make sure that all of these people get paid on time...