Revenue of popular company by this writer (6)
I believe the answer is:
income
'revenue' is the definition.
(both can mean money made)
'popular company by this writer' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'company' becomes 'co' (abbreviation).
'by' means one lot of letters go next to another.
'this writer' becomes 'me' (the person who wrote the clues).
'in'+'co'+'me'='INCOME'
'of' is the link.
(Other definitions for income that I've seen before include "Earned or unearned revenue." , "Money coming in" , "Financial gain accruing over a given period of time" , "Remuneration or earnings" , "Money received as wages, interest etc" .)