All in all, this clearly seems to be a market in which big retailers could profitably apply their gigantic scale, existing infrastructure, and proven skills in the management of product ranges, logistics and marketing intelligence.

【翻译】总而言之，这看起来显然是一个市场，（在此市场里）大型零售商可以利用其庞大的规模、现有的基础设施和在产品系列管理、物流和营销智能方面的熟练技能。

1. 主句：this clearly seems to be a market

2. 定语从句：in which big retailers could profitably apply their gigantic scale, existing infrastructure, and proven skills in the management of product ranges, logistics and marketing intelligence

3. 在定语从句中：

主语：big retailers

谓语动词：apply

宾语：3个并列宾语their gigantic scale, existing infrastructure, and proven skills

定语：in the management of product ranges, logistics and marketing intelligence，修饰skills，介词in 说明在哪一方面的。