It appears that until this week, iOS device users in China have had to pay for their Apps in US Dollars. One of the reasons that Apple haven’t allowed purchases in Chinese Yuan is because it costs them a fee when purchases are made in different currencies. It wasn’t worth it for China as they didn’t make enough purchases on the App Store.
To maximize sales from China, Apple have now allowed purchases to be made in Yuan. They believe that this will encourage Chinese users of iOS devices to make more purchases from the App store.
It turns out that Apple will only lose money from doing this as the services work out cheaper for people to buy. Apple are expecting a large amount of people from China to use their services now it is in their native currency.