将下面的一段英文文本翻译成中文，确保翻译准确无误，自然流畅。 
Traditionally, businesses targeted the rich customers because they believed that only the rich had disposable income. Recently, companies have shifted their focus towards the middle class as they make up a significant portion of the population and have increasing purchasing power. This shift in focus has resulted in changes in product and marketing strategies.
传统上，企业的目标客户是富裕人群，因为他们认为只有富裕人群才有可支配收入。最近，企业已经将重点转向中产阶级，因为他们占了人口的重要部分并且拥有越来越强的购买能力。这种关注点的转移导致了产品和营销策略上的变化。