I'm 19, I make good money but I can never get enough of it - I literally spend hundreds of dollars every day into new ideas, products and investments for my own product sites which don't give me an immediate return, but pay off in the long term.
I make much more money as an advertiser than as an affiliate, mostly because I started out by going straight into online business as opposed to affiliate marketing.
Oh, and I'll be starting a joint degree in Computer Science and Business Studies this year after dropping out of my Politics degree last year. Twas a damn good decision.