TL;DR I rewrote a product's differentiators after noticing four of five were claims any competitor could paste onto their own page word-for-word. The test: could a rival put this exact sentence on their site and have it be just as true? If yes, it's a category description, not a difference.
Source: [Dev.to](https://dev.to/nasrulhazim/the-differentiator-test-if-a-rival-can-copy-the-claim-it-isnt-one-2768)