Economics of being a real estate agent?

[Michael Frank]

Hi, I was wondering if someone could give me a quick briefing on the economics of being a real estate broker, particularly in CA? 

So you make 2.5%ish per home? If you're the buyers agent, what are the other fees involved with that?

if you work for a big firm, how much of that do you keep?

How much does licensing and other stuff cost?

Why do so many people work for big firms? The stead pay check? The office? the leads? 

Any and all information would be great.