[sama]

Luck is necessary but not sufficient. But I left it off the list because telling people to "be lucky" is difficult to act on.

[seregine]

I've recently seen interesting arguments that optimism creates luck by enabling you to recognize more opportunities.

E.g. http://www.damninteresting.com/you-make-your-own-luck/

[ronilan]

There are things other than luck that are out of the control of the startup.

Here is a quote: "In a great market -- a market with lots of real potential customers -- the market pulls product out of the startup."