Selling feature everybody studies after a little time by day (3,3,4)
I believe the answer is:
all mod cons
'selling feature' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'everybody studies after a little time by day' is the wordplay.
'everybody' becomes 'all' (I've seen this before).
'studies' becomes 'cons' (to con is to study or revise).
'after' is a charade indicator (letters next to each other).
'a little time' becomes 'mo' (a 'mo' is a short amount of time).
'by day' becomes 'd' (abbreviation for day. I am not sure about the 'by' bit.).
'cons' after 'mod' is 'modcons'.
'all'+'modcons'='ALL MOD CONS'
Can you help me to learn more?