The phrase "to guarantee a hit" means to make sure that something will be successful or popular.
Sentences with «to guarantee a hit»
But, the presence of these celebrities don't always guarantee a hit movie. (dvdsleuth.com)
Helps get them on the system and adding Mario to it is going to almost guarantee a hit for Ubisoft. (letsplayvideogames.com)
I can only think of messi, ronaldo, suarez, aguero, lewandoski, tevez and neymar as the only goal scorers that will guaranteed hits at the moment and would be worth any investment but they can't be bought. (justarsenal.com)