Apple generated nearly $30 billion in revenue in China in 2013

"In China, if you look at the last 12 months, we’ve done $29 billion to $30 billion in revenue there in greater China. I don’t know of any other American company that does that kind of business in China or anywhere close. These are things that we’re really proud of and we worked really hard at."

Source:  Tim Cook of Apple, interviewed in WSJ 7th February 2014