Answer:
1) Level of experience of the founders
Step-by-step explanation:
Start ups pursue innovation, and many times that is very hard to accomplish. As any new entrepreneurship, start ups require a lot of work, time and effort from their entrepreneurs. And their success is based on the success of its founders. It always amuses me how giant companies started from basically nothing, but hard work and intelligence combined.
If Steve Jobs hadn't been brilliant, computers would probably still be the size of a small room or even a building. Was he lucky? Of course he was lucky and got help at the right moment but without his experience and education there would be no magic. The same applies to Google, Amazon, FB, etc. Before they turned into huge corporations, all they had was human capital.