Well, it's not the only way, but in China the military is a business. The military, as a business, sells organs. It's not their only source of money, but it's a big source. In fact, there was a military hospital that had on its website, “Selling organs is our main source of funds”. Like everything else, I quoted it, and they took it down.
On February 5th, 2013. See this statement in context.