China has already surpassed the United States as the world's largest smartphone market, but apparently that impressive feat isn't enough for the year. The country is also amassing an enormous Android army that will measure larger than the entire U.S. population.

Fortunately, we're talking about smartphone operating systems here and not murderous cyborgs incapable of feeling love, but even so, the news is impressive. By the end of 2013, China is expected to be home to more than 300 million Android device owners. Compared to 2012, when China had over 224 million Android owners, that's a 34 percent increase. That would be an impressive number even if it accounted for the country's entire smartphone market, not just Google's massively popular OS.

The crazier thing is that the Android population might as well be China's entire smartphone market. A mind-numbing 86 percent of all smartphones sold in China are running on Android. On top of that, 73 percent of all phone sales are smartphone sales. Considering that China's population numbers more than one billion people, it's possible that in the next couple of years Android's dominance can reach even more dizzying heights.

You'd think that with such market supremacy, Google would be trumpeting these stats left and right. But it's not, and a major reason why could be that Google isn't making any money off of its success.

Since Android is open-source, it can be used by any company for free. And, as Quartz points out, that's exactly what Chinese manufacturers are doing.

"While Android succeeds in China, it's largely versions of Android uncoupled from Google's 'official' version," Christopher Mims writes.

Since most apps in China are sold through the country's own app stores, Google can't even force phone makers to use its version of Android for Google Play access. They don't need it. On top of that, Google's search engine doesn't even hold 5 percent market share in China, meaning its advertising revenues are negligible.

As Mims concludes, "Google is now sponsoring the mobile software R&D for what will soon be 300 million Android-based Chinese phones — and, in China at least, getting virtually zero return on its investment."

And in the world's largest market, that has to hurt.