A speed test measures a few warm pages from your own desk. Your visitors get all the others. How to measure the one number that describes a cache honestly, the hit rate, and what quietly ruins it.
A page cache only makes the second visit fast; someone always pays for the first. What a cold cache costs, why the long tail never warms itself, and how event-driven preloading closes the gap.
A setup checklist for caching a WooCommerce shop with MilliCache: find your cache boundary, put each cookie on the right list, decide about the checkout and signed-in customers, and verify all of it.