Gold is physical that is what most people like about it. While physical and a less volatile object to buy, it is also a very much in demand by the people for oneself as a treasure or jewelry and or perhaps as a technological needs because some components like CPU of a computer and other components are gold plated. Gold acts also as the basis for a country's economy. So this could be the reason why China would like you to buy it. And maybe because they have so much gold and silver which when bought by others could also make them rich.