Szymon Maksymiuk, who works for a tourist information centre in Szczecin, said the stories of people travelling to see Gacek were "mindblowing".
"There was a guy from Norway who took a flight. He claimed Gacek drove him to make the decision of coming here," Maksymiuk said. "Because of Gacek, tourism has increased enormously, far beyond my expectation or imagination."
Some fans attribute Gacek's fame to his confidence and cute face, others say it is his celebrity status that is attracting visitors to a city already known for its Pomeranian Dukes' Castle, parks and picturesque riverside setting.
Among those wanting to see Gacek was history student Kherlen, who comes from Mongolia and lives in Germany.
"I'm looking for that cat named Gacek," he told Reuters. "I hope I will find it, maybe today, maybe tomorrow."