Is it useful for calligraphy training institutions to sweep the building?

It is useful for calligraphy training institutions to sweep the building. According to the query of relevant information, the way of sweeping the building can be well publicized in the early stage, so it is useful for calligraphy training institutions to sweep the building. The word "sweeping the building" first appeared in insurance marketing, credit card promotion and other industries, meaning door-to-door sales. Later, sweeping the building was no longer limited to the marketing field, as long as it was a door-to-door visit, it could be called sweeping the building.