I haven't seen this movie, but when I was in China I heard about this kind of stories in TV and in newspaper. How to say, many parts of China is still quite poor. In some villages, farmers lives so poorly that people from developed countries will never imagine, in fact, I couldn't imagine myself (I grown up in the southeastern China, which is the richest place in China). These farmers are not well-educated, and they see that selling blood is the quickest way to make some money. But if they go to the official places for donating, it will be fine. And this wouldn't happen. They go to some underground or unofficial sites, where the purpose of the owners of those sites is to make money while to pay little.
I think the main problem in China is that now the southeastern provinces are too rich, whereas the western ones are too poor. There are two extremes.
I think the main problem in China is that now the southeastern provinces are too rich, whereas the western ones are too poor. There are two extremes.