Profit for returning salesmen (7)
I believe the answer is:
promote
'profit' is the definition.
(thesaurus)
'for returning salesmen' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'returning salesmen' becomes 'mote' (I can't explain this - if you can you should believe this answer much more).
'pro'+'mote'='PROMOTE'
Can you help me to learn more?
(Other definitions for promote that I've seen before include "Publicise; raise in rank" , "Encourage - upgrade" , "Support, encourage" , "Move up -- market" , "Raise to higher rank" .)