Own CDN with traffic management
Lets say you have some idling vpses and want to build a smaller CDN just for your own website. How would you manage the traffic limits on each of those vpses? It's not about the locations around the world in this case but rather an optimal usage of all your vpses bandwidth and traffic and amount.
Some vpses only have 200gb of traffic included, others have 1tb or 500gb. So with a handful of vpses you could host your stuff and use up to ~5tb traffic split across 10 vpses. How would you do that? Best would be if you could additionally be able to do this on the dns side so you can use dl.domain.com or cdn.domain.com