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
How about asking first?! It's really annoying and completely useless for me! And 7 days is far too long when you're unlucky enough to be a part of that 0.3 %