The big difference IMO is that Microsoft and Apple have successful business models, where Facebook is still searching for one. There is less risk building on a

The big difference IMO is that Microsoft and Apple have successful business models, where Facebook is still searching for one. There is less risk building on a platform that has a clearly defined and profitable business model. Remember the widget economy? Facebook widget funds? With one redesign, Facebook singlehandedly wiped out the market. You will always rely on third party products and services, it's unavoidable. Make sure you own the work that is core to your value prop, and only take on acceptable risks when outsourcing.