... Tips from shopping online (service only average)
I believe the answer is:
so-so
'average' is the definition.
(thesaurus)
'tips from shopping online service only' is the wordplay.
'tips from' suggests taking the first letters (I've seen 'tip from' mean this).
The initial letters of 'shopping online service only' is 'SO-SO'.
(Other definitions for so-so that I've seen before include "Of average quality" , "Tolerable, indifferent" , "'Passable, middling (2-2)'" , "Informally, only moderately good or well" , "Rather middling" .)