The French president went to China this week and came back with big deals for French firms. But do state visits really help to boost business ties? Stephen Carroll asks Sébastien Badault, the managing director of Chinese internet giant Alibaba in France. Also in this programme, we look at what's changed in Iran's economy in the two years since sanctions were lifted. Plus, we tell you the story of a crumbling French chateau that's been saved by the internet.