Changing Thumbnails on YouTube Is a Good Idea, Right?

Don't change the thumbnails on your videos, you're just tricking existing viewers to watch it. The number of thumbnails I had that were just the title in like block cap letters as the thumbnail itself was surprisingly high. One of the things I was trying to avoid was making thumbnail or title changes. If what I saw on the back end was, oh, there's a bump in viewers, but they're all returning viewers who already watched this before. That's a bad one. And I'm going to change that. What I'm trying to have is YouTube actually show that to new people.