Sharing answers to top q's we’re seeing about the thumbnail experiment: – Custom thumbs aren't going away – 99.7% still see the creator's custom thumbnail – A lot of creators use auto-generated thumbnails, this test helps improve them for those using them: https://goo.gl/A7oDmr
Why dont you only do that in videos that didnt have a custom thumbnail attached? That way everyone who took time making a thumbnail isnt pissed, and the people who didnt obviously dont care that much about the thumbnail so use them as guinea pigs. Everyone wins