Specialised corner of the market (5)
I believe the answer is:
niche
'specialised corner of the market' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for niche that I've seen before include "Special location" , "Specialised corner of the market" , "Recess - suitable position" , "A small recess or easy job" , "Specialized market" .)