The writer enters bookshops maybe — to promote these? (7)
I believe the answer is:
stories
'promote these?' is the definition.
The definition suggests an adverb but the answer is not.
'the writer enters bookshops maybe' is the wordplay.
'the writer' becomes 'i' (the person who is writing these clues).
'enters' is an insertion indicator.
'bookshops maybe' becomes 'stores'.
'i' put into 'stores' is 'STORIES'.
'to' is the link.
(Other definitions for stories that I've seen before include "Floors" , "Accounts" , "Lies" , "House sections" , "See 21" .)