Freda felt that I Vampiri did not succeed financially in Italy due to the country's audience reluctance to an Italian interpretation of the horror genre. For Freda's next film, Caltiki – The Immortal Monster, he used an English pseudonym of Robert Hampton to give the impression that the film was not Italian.
Freda believed that I Vampiri did not perform financially well in Italy due to the Italian audience's reluctance to accept an Italian interpretation of the horror genre. For Freda's next film, Caltiki – The Immortal Monster, he used a pseudonym, Robert Hampton, to disguise the film as being English-made.