It should read "He promotes the city around the world." It means he promotes the city all over the world, and not just locally or only in one market. For instance, if I was in charge of promoting Chicago's food festival, I could promote it: 1) only in Chicago 2) only in the state of Illinois 3) only in the central United States 4) only in other big cities in the United States 5) only in US and Europe (Chicago has a large Polish demographic) 6) or everywhere around the world.