That's really not the point. It's not that execution will guarantee success. It's that execution is the differentiating factor (apart from luck) regarding various companies attempting the same idea. Neither Facebook, Twitter, or Groupon (can't really tell about AirBNB) where innovators on the ideas per se. Social networks for college students, message streams, and online deals/discounts, where by no means new innovative ideas. Their execution set them apart and with a bit a of luck and good timing they made it big.
It's not that ideas don't matter. It's that 'new' ideas are almost always not new and have been done to death. What the idea is has never been a point being refuted by most people, what's being refuted is that the idea is what makes the difference. Lot's of people had the idea of online restaurant reservations, but that doesn't mean that everyone that brings that idea to fruition we'll be successful. It's a matter of execution that will increase any possibility of actually making it.
It's not that ideas don't matter. It's that 'new' ideas are almost always not new and have been done to death. What the idea is has never been a point being refuted by most people, what's being refuted is that the idea is what makes the difference. Lot's of people had the idea of online restaurant reservations, but that doesn't mean that everyone that brings that idea to fruition we'll be successful. It's a matter of execution that will increase any possibility of actually making it.