For the past two days I've been redoing some of my thumbnails. The ones I replaced were on videos that we getting very few views. The one that convinced me to redo them had 22 views after several days. I didn't like the thumb much anyway, but it was one of those that I did after the video, and when I was getting tired. I changed it at 5:30pm on the 10th, and as I said, it had 22 views at that time. It is now 7pm on the 12th and it has had 82 views. So, the lesson for me was, pay attention to the thumbnail, make it as appealing as you can because it really does matter.