What are the most important keys to success?

I would agree with prashu. Hardwork and Luck are two things that makes one successful. I know of a lot of people who works so hard, day in and day out, but still living a meager life. While, there are also people who just happens to be in the right place and the right time. As for my personal experience, I've always been a hardworking person, but I didn't get very lucky at my first job. But, on the 2nd company I joined, I got promotions after promotions, due to both hardwork and right timing (luck).

Yes, I believe hard work is a universal law for most people to be successful. To play the devil's advocate, some people would say that work smart and not hard is the key to success. Do you think this belief or saying has some value or it is not valid? I guess for me, I think it could work for people who has discovered a smart system that makes them earn well with less work to do. But I think if you work hard with that type of smart system, your income would be even bigger...that's logic, isn't it. This idea is a bit confusing, any thoughts or opinions about this?