Runaway success and Smash hit

Smash hit and runaway success are semantically related. In some cases you can use "Smash hit" instead a noun phrase "Runaway success".

Smash hit noun - An unusually successful hit with widespread popularity and huge sales (especially a movie or play or recording or novel).

Runaway success and smash hit are semantically related. You can use "Runaway success" instead a noun phrase "Smash hit".