Trio broken by commercial ban - that's shabby (10)
I believe the answer is:
threadbare
'shabby' is the definition.
(I've seen this in another clue)
'trio broken by commercial ban' is the wordplay.
'trio' becomes 'three' (synonyms).
'broken by' indicates putting letters inside (inserted letters break into the word).
'commercial' becomes 'ad' (abbreviation for advertisement).
'ban' becomes 'bar' (I've seen this in other clues).
'ad'+'bar'='adbar'
'three' enclosing 'adbar' is 'THREADBARE'.
'that's' is the link.
(Other definitions for threadbare that I've seen before include "the worse for wear" , "poor" , "Shabby" , "Tired" , "deprived of nap" .)