Sales talk? It’s not quite the model (6)
I believe the answer is:
patter
'sales talk?' is the definition.
(thesaurus)
'not quite the model' is the wordplay.
'not quite' means to remove the last letter.
'the model' becomes 'pattern' (pattern is a kind of model).
'pattern' with its last letter removed is 'PATTER'.
'it's' acts as a link.
(Other definitions for patter that I've seen before include "Rapid and glib speech, perhaps in selling" , "Comedian's rapid jokes" , "Line of gab" , "idle talk" , "Noise of fast light steps" .)