What are the characteristics of "professional" poetry?

I have recently done some work on what the differences are between poems written by amateurs and those written by professionals. Essentially, the most significant characteristics of " professional" poetry is that it is more concrete and contains less sentiment than poems written by " amateurs" . The full paper is available here: http://ssrn.com/abstract=2208452.
I look forward to your responses.

The connection of Characterism and professionalism is not direct, because the Characterism even though surfaces through out practice and discipline, is personal and depends on each individuals. This characteristics also would never become like the ones of others and they are concomitant with personality and individuality.
Thorough out hard work we discipline our characters and the " characteristics" of our works. We find them, develop them; our poetry could never have the same characteristic as other poetry unless we plagiarize or turn to copy cats.