That is a very common "tech startup world" meme, and very damaging, in my opinion. Persistence is in fact utterly useless unless you're persisting at the right things.

My experience, on the contrary, is that, at least outside the Valley, many founders persist years past the point where they should have given up and done something else instead. And the reason they fail is not that they didn't persist long enough, but that they lack the skills to implement their ideas (usually on the customer development / marketing side). I've seen examples of both skilled founders pulling off apparently boring ideas, and unskilled ones failing at apparently good ideas despite persisting for years.

If anything, my observation is that the most reliably successful people I know are not persistent at all - or rather, they're persistent at the overall game of entrepreneurship, rather than at doggedly following a dead startup into the grave. Skilled and experienced entrepreneurs have the guts to recognise that what seemed like a brilliant genius idea 3 months ago is in fact a total waste of time, and do something else instead. The biggest differentiator, though, is skill.

Moreover, whereas "being persistent" or "having great ideas" is a character trait that is quite difficult to change, anyone can learn skills and improve their chances this way.

Finally, looking at the example which you picked, Plancast persisted for 2 years - a year and a half after, in the founder's words, "things began to stall". That seems reasonably persistent to me. Of course, it's easy to stand on the sidelines and say "they should have kept trying for longer" - because it's not your life that's elapsing while they work on that dud startup idea.

If you're working on a big idea that is slightly ahead of its time, then persistence can pay big dividends -- check out the story of Pandora (http://www.businessinsider.com/pandora-story-2011-6).

If you're working on a smaller, highly tactical idea then persistence is often a waste of time. Anyone who meets a lot of startups will see many ideas that just aren't going to work. The sooner the founders realize it and move on, the better off they are.

"Nothing in the world can take the place of Persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. The slogan ‘Press On’ has solved and always will solve the problems of the human race." — Calvin Coolidge

Does anyone really do anything assuming the idea will fail though? Unless of course it's an experiment where the outcome doesn't matter - taken as a form of education.

It takes persistance foremost. For myself, I knew there were risks though I would continue to find ways to reduce risk - whether it was problem solving and planning, figuring out what I needed to do next to reduce the risk. This required something at a lower base level than willing to take on risk.

So what's more base than risk? Being able to manage yourself during a challenge, learning your own limits, what you are capable of - which takes self-awareness. The more I've learned myself over the years, my limits, the better I've become at self-regulating, and the better I know what I need to succeed. Any money I've spent so far I've considered an educational expense.

Life's all about learning, and hopefully being able to find enjoyment and being able to help others hopefully find enjoyment, too.

I agree that those are important... but they're not skills!

Skills are things you do with varying levels of competence, not things you are. "Willingness to take risk" is not a skill. "Passion" is also not a skill! "Risk mitigation" would be a skill, but I think it's not as core as the 12 I listed.