I will just say, I think the idea itself of a trailer is to build up anticipation for a big event. If you're just planning on releasing a "normal" video, it might seem slightly anti-climactic when they finally watch it. However, if you're realizing some sort of big content out of the ordinarily and you're trying to build up hype for it, then a trailer could work. For example, every summer we do our "Backyard Olympics" and it's a big deal on our channel, and people pick teams and cheer for their favorites... so we put out trailers beforehand to get people excited and pumped. But if we just did a trailer for our normal weekly episode, I think people would be disappointed when they actually watched it, lol. Just my thoughts.