[hnlmorg]

Without knowing more about the application, I'd guess probably caching and/or scaling. If you only need 1 payload then that can be statically generated and cached in your CDN. Which in turn reduces your dependence on the web servers so few nodes are required and/or you can scale your site more easily to demand. Also compute time is more expensive than CDN costs so there might well be some cost savings there too.

[brundolf]

This was basically it. The dataset was the same across users so caching was simple and efficient, and the front-end had no difficulty handling this much data (and paging client-side was snappier than requesting anew each time)