The hefty price underscores how Wal-Mart is trying to compete more aggressively and effectively for younger and more affluent customers as it has seen its online business growth slow despite big investments in distribution centers and expanding services.

【翻译】这个高昂的出价凸显了沃尔玛如何试图更积极、更有效地争取到更加年轻、更加富裕的客户，因为它已经看到了自己的在线业务增长缓慢，尽管在配送中心和扩大服务方面进行了很大的投入。

【分析】as it has seen its online business growth slow despite big investments in distribution centers and expanding services 是原因状语从句。

1. as从句用现在完成时，往往表示“原因”，很少表示“时间”。前面我已解答过网友类似的问题。

2. underscore：强调；突出。

3. compete for：为得到......而竞争；争取到