When I was half way through college I decided I no longer wanted to be in school. I emailed a bunch of startups saying essentially "Your company sounds cool. I'll come work for you for the summer for free as long as we set up some kind of goal system where I can get a job offer at the end of the summer." I ended up getting two offers from that and never looked back. I didn't end up lasting 4 years there like you, but I am definitely glad I did it.
Ironically enough, now that I'm somewhat into my career I can't see myself doing something like that again, which is too bad. I've picked up some risk aversion along the way :(