well, you are betting that you will get a dividend at a much later point in the future because of the growth you think you will realize. if Amazon makes $100 it can either give it to you now, or reinvest it and give you the reinvested result much later. It makes sense to give you the $100 now, if they don't see any good investment opportunities. But they think they do, and market agrees with them, hence massive growth in stock price over the last 3-5 years.
