The way those smart fellows have achieved this is by exploiting Apple's own bulk enterprise licensing tools. The tools are usually used by companies to distribute apps to their employees more easily, but it looks like messy things can happen if they fall in the wrong hands. Utilizing the tools, the pirates are now offering paid apps for free through their site. The "service" is only available in China, but according to some reports, it's possible to take advantage of it if you use a proxy server, though we don't encourage anyone to try it.
The fun part is the admins' explanation of their actions. Apparently, they "believe" that using the iTunes platform can prove to be a bit difficult for Chinese users, which is why they are offering a new way of getting applications. According to them, the percentage of jailbroken phones in China since the service's launch has dropped from 60% to around 30%, which, however, doesn't really matter that much, considering that those non-jailbroken users are still getting pirated content. It would certainly be interesting to see how Apple reacts to that...
Here's the full message by site:
Statistics have shown that a significant amount of Apple users are Chinese based. However, the fact is that in China, a large number of Apple users are not very familiar with the iTunes system and how to effectively manage it.
In order for Chinese Apple fans to download applications securely, Kuaiyong developed its own method of giving users access to thousands of free apps without having to jailbreak their devices. Kuaiyong offers detailed descriptions of apps, free app download trial, IOS device management and visual and audio file backup system. IOS system backup and recovery features will also be released in the very near future.
Our goal has always been about bringing Chinese Apple users with quick, convenient and pleasant IOS experience. Since the introduce of Kuaiyong, the proportion of jailbreak in China has declined dramatically from 60% to around 30%. Kuaiyong will hold on to this goal in the future and we would like to see more support for Apple as well as Kuaiyong."