They're strikingly successful (4)
I believe the answer is:
hits
If this is the answer, I'm afraid I cannot explain it.
Can you help me to learn more?
(Other definitions for hits that I've seen before include "welcome in the theatre world?" , "Top pops" , "that please the public?" , "In the 60s these were 'groovy'" , "Raps - successful recordings" .)