Poor net sales causing delay (8)
I believe the answer is:
lateness
'delay' is the definition.
(I've seen this before)
'poor net sales' is the wordplay.
'poor' indicates an anagram.
'net'+'sales'='netsales'
'netsales' with letters rearranged gives 'LATENESS'.
'causing' acts as a link.
(Other definitions for lateness that I've seen before include "Delay" , "Unpunctuality" , "behind" .)