This oddly includes a success for an island (6)
I believe the answer is:
tahiti
'island' is the definition.
(Tahiti is an example)
'this oddly includes a success for an' is the wordplay.
'oddly' means one should take alternating letters.
'includes' is an insertion indicator.
'a success' becomes 'hit' (hit is a kind of success**).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'an' becomes 'a'.
The alternating letters of 'this' are 'ti'.
'hit' after 'a' is 'ahit'.
'ti' placed around 'ahit' is 'TAHITI'.
(Other definitions for tahiti that I've seen before include "South Pacific island, linked to Paul Gauguin and Robert Louis Stevenson" , "South Seas island, capital Papeete" , "Main island of French Polynesia" , "part of Polynesia" , "South Pacific island, associated with Robert Louis Stevenson" .)