Final answer:
The cloud benefit described is 'economies of scale,' where costs per user decrease as the number of subscribers increases, enabling competitive pricing for cloud service providers.
Step-by-step explanation:
The cloud benefit that describes a situation where a cloud service provider's costs per subscriber are reduced as the number of subscribers to a public cloud increases is known as economies of scale. This principle is not only applicable to the manufacturing industry, where larger factories benefit from lower average costs compared to smaller factories but is also relevant in the context of cloud computing services. As the subscriber base grows, the cost of operation per subscriber decreases, which allows cloud service providers to offer competitive pricing while maintaining or increasing profitability.