In my previous post I did praise a lot about salary. However! there is a catch!
I once thought, when I am rich I would make a company that allows flexible time. If you are done with the work early you should be able to go home sooner. If you need to be absent tomorrow then you can work overtime for 2-3 days to make up for one man day that you will be absent. Why can't you work from home and measure work based on your task? Or other thoughts along these line.
Then I talked these with my friends why no such company exists in common. The answer is surprising, it's all because the after effects of a salary system!