High CDN Cost = Content Delivery

CDN's cost between 20 and 60 on major CDN's from Amazon, Google, ..., after negotiation and willingness to park lots of money and commit per month it might be certain discount.
Other specialized CDN's can be around 10 per TB if services from e.g. Europe or US, smaller CDN's are much more expensive.
Managing these CDN's is expensive and not easy job.

This means to service 10m people, it would cost about 1 to 2m USD per month just for CDN alone.

CDN Pricing Amazon

Remark no fees included for HTTPS requests, but should be ok for volume we are talking about, if app is made in right way.

	United States, Mexico, and Canada	Europe, Israel, and Türkiye	South Africa, Kenya, Nigeria, and Middle East	South America	Japan	Australia and New Zealand	Hong Kong, Indonesia, Philippines, Singapore, South Korea, Taiwan, Thailand, Malaysia, and Vietnam	India
All Data Transfer	$0.020	$0.020	$0.060	$0.125	$0.060	$0.080	$0.060	$0.160

Remark no fees included for HTTPS requests, but should be ok for volume we are talking about, if app is made in right way.

	< 10 TiB	10 TiB-150 TiB	150 TiB-500 TiB	> 500 TiB
Asia Pacific (including Hong Kong)	$0.09	$0.06	$0.05	On demand
China	$0.20	$0.17	$0.16	On demand
Europe	$0.08	$0.055	$0.03	On demand
North America (including Hawaii)	$0.08	$0.055	$0.03	On demand
Oceania	$0.11	$0.09	$0.08	On demand
South America	$0.09	$0.06	$0.05	On demand
All other destinations (including Mexico, Central America, and Middle East)	$0.09	$0.06	$0.05	On demand