Summarised what links banks in publicity material (8)
I believe the answer is:
abridged
'summarised' is the definition.
'what links banks in publicity material' is the wordplay.
'what links banks' becomes 'bridge'.
'in' is an insertion indicator.
'publicity material' becomes 'ad'.
'bridge' placed inside 'ad' is 'ABRIDGED'.
(Other definitions for abridged that I've seen before include "Epitomised" , "Cut short - big adder (anag)" , "Shortened as book may be" , "Abbreviated, contracted" , "Shorter" .)