Just a small little trick but very powerful in the long run. When you upload a video, like it. then disable ratings, youtube is testing out new search page to show ratings so when you do that it shows up as "100% like" rather than nothing so it looks like everyone who watched the video liked it. Just make sure you do this process fast before someone watches the video and dislikes it before you have a chance to disable it. I tend to do the ratings whilst it's uploading since it doesn't appear in searches until it's done processing.