I worked on a SaaS CMS. A major consumer PC manufacturer was a customer and their "Welcome to your PC" app would pull their news feed from our system. People would turn on their PC and they'd pull a little JSON. 100s of Thousands of request per day, no big deal. The manufacturer decided that they wanted the updates to show up for everybody at the same time on the hour. Serving 100k req/s for a minute is a much different problem to solve.