The humble public potty has the potential to boost tourism and set the pace in the country's broad campaign to upgrade products made in China.

President Xi Jinping called on Monday for continued efforts to upgrade the country's toilets as part of an ongoing "toilet revolution" campaign. But why has China started this campaign, and why has its top leader personally spoken out on this seemingly petty issue? Xi's latest instructions provide some answers.

To understand it better, it's necessary to look into what Chinese toilets were in the past and the far-reaching impact of the revitalization project.