The best way to improve delivery is to replicate the content on the edge servers. However, keeping all the content on the edge isn’t always the most efficient strategy. Mid-tier caching enables a set of rules to shield your origin from new requests.
If some of your content should expire, you can chose to preserve it at the mid-tier to be reactivated instantly. Websites and Applications with large libraries and/or high asset turnover make the most of mid-tier cache to protect their origin.