As my college professor told me many years ago, "people do business with you because they LIKE you more than any other reason. Continue being likeable and you will be successful."

I will say that this is true more for entrepreneurs that for Corporate America. I had many successful years as an independent consultant where being likeable was more profitable than being most other things. But I learned when I took the corporate job that it really seems like assholes get ahead more than anyone else. Or as I say, "the biggest bully wins." (Unfortunately, I am not a very good bully.)