In economics class, if I remember, that the long term profit rate of a company should be zero. I mean that in an efficient market that a company should not be able to make a profit beyond paying its employees and covering its cost -- if I remember. If this is true then wouldn't that imply that the long term return for a company should essentially be zero or the no more then the value of the physical resources. One can see this, for example, when a second mover product comes out and increases competition, i.e in the tablet space, game consoles, etc. How does one reconcile this idea that the long term return for company should be zero with the idea that the stock market should always keep growing, i.e stocks for the long run? Thoughts?