The main application I run operates in 7 countries globally, but the US is the only one that has enough usage to require additional capacity during the workday. So out of 720 hours in a 30 day month, cloud scaling allows me to pay for additional capacity for only the (roughly) 160 hours that it's actually needed. It's a significant cost saver.

And because the scaling is based on actual metrics, it won't scale up on a holiday when nobody is using the application. More cost savings.