Publication by Web is something attractive (6)
I believe the answer is:
magnet
'is something attractive' is the definition.
(I've seen this before)
'publication by web' is the wordplay.
'publication' becomes 'mag' (abbreviation for magazine).
'by' says to put letters next to each other.
'web' becomes 'net' (synonyms).
'mag'+'net'='MAGNET'
(Other definitions for magnet that I've seen before include "Attractive item" , "One that attracts" , "Source of attraction" , "Powerful attractor" , "it could be a draw?" .)