美国人民这么富有，为什么普通美国人需要卖血维生？

Core Insights - The article discusses the phenomenon of paid plasma donation in the United States, highlighting that there are approximately a thousand blood donation centers nationwide, primarily located in impoverished areas [1] - It raises the question of why such a practice exists in a prosperous country like the United States, suggesting the presence of a "reward system" for donors, including incentives for referrals and full attendance bonuses [1] Industry Overview - The blood donation industry in the U.S. is characterized by a significant number of centers that operate in economically disadvantaged regions, indicating a potential market for paid plasma donation [1] - The establishment of a "reward system" within these centers suggests a structured approach to encourage donations, which may reflect broader socioeconomic issues [1]