The successful person is the one who does the most good, irrespective of his bank balance. Therefore the businessman who behaves ethically is _by definition_ more successful than the one who is prepared to behave unethically.
The definition of success has nothing to do with morals. I'm certain there are a lot of unethical people making money who consider themselves huge successes. Similarly, there are a lot of people with no money at all who think the same about themselves.
The question has to do with material wealth. Any answer that deal in anything but material wealth would be sidestepping the question. Godin doesn't deal with ethic, he deals with profit and results. It's why he's as famous as he is. You might disagree with that method, but that's how he works and it's what's made him a success.
My point is that for a 'spiritual person', true success is aimed for in the long-term measure - the one by which we are ultimately judged - whether deemed to be judged by ourselves or a third party. So to ask, in the context of 'spiritual business' about success, meaning financial success, is something of a contradiction in terms.
I'm an atheist. I don't believe in an afterlife. What happens in this life is all we get. To me, any effort spent hoping for anything else is folly.
I look at "success" from a neutral lens. There isn't just one form of success. In my mind, success-through-great-product is a desirable success. So is success-through-never-needing-money. Both of these can be achieved through ethical failure. You can make lots of money through breaking laws. You can break rules to more easily design your product. The question asked was: can people succeed at all by being clean? And Seth's answer was yes, because the Net exposes more to people and it stops people from being as easily dirty. That's a good thing! Absolutely!
Just don't take that answer and turn it into a matter of morals being all that matter, because they don't. Amoral people are still succeeding in the world, and I doubt they'll be punished for the crimes they've committed. Some might. Certainly not all. His point was that you didn't have to be dirty, and that's a positive enough answer without moral certainty becoming involved.
"Success is the percentage of your life you control" -Chuck Klosterman
If your goal is to become rich no matter what, you can become very successful as a drug baron.
It looks like you're confusing successful and respectable.