Payment makes them better advisers (8)
I believe the answer is:
tipsters
'advisers' is the definition.
(I know this)
'payment makes them better' is the wordplay.
I cannot really understand how this works, but
'payment' could be 'tip' (tip is a kind of payment) and 'tip' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tipsters that I've seen before include "They give advice about horse races" , "They give hints about horse races" .)