The second video I released on my second channel flopped, hard... Until I changed the thumbnail, and it skyrocketed in views and built the foundation of the entire channel.
From Sixty views a day to over a thousand daily average views.
Now, two years later this video has made a total of 900$ and still averages one thousand views a day.
All by simply improving the clickability of the video.
Taking the CTR from 5.5% to 12.2%