Do you think there is a code for success?

Or does luck play a factor...?

Why do some people become rich and famous off of youtube and others don't?
Why do some talented actresses make it and other talented acresses don't?
How do some random businesses just take off and become unexpectedly popular and others don't?

I guess what I'm asking is, do you believe that luck is a factor in success?

And I'm not talking about success based on opportunities that are handed down from mommy and daddy. I'm talking about success starting from the bottom up.

What are your thoughts?