"They call stock options a lottery ticket. I call it insurance. It sucks to have worked at a startup which did make it big and to not have made anything off it. Incidentally, I know quite a lot of people who either forfeited their stock options or sold them very cheaply, on the theory that equity is worthless. Trust me, if you're working for a startup, this is the one accident you want to be insured against."
Calling it "insurance" is probably taking it too far, but there is merit to this analogy, and it certainly is the case that equity is not worthless. With many startups, you can negotiate a decent base salary, and still receive enough equity to make you very well of if the company does take off.