Stick promotion in this place (6)
I believe the answer is:
adhere
'stick' is the definition.
('adhere' can be a synonym of 'stick')
'promotion in this place' is the wordplay.
'promotion' becomes 'ad' (ad is a kind of promotion).
'in this place' becomes 'here' ('here' can be a synonym of 'in this place').
'ad'+'here'='ADHERE'
(Other definitions for adhere that I've seen before include "Stick L" , "Header (anag)" , "Remain attached" , "Agree" , "Stick with header" .)