popular topics

Hey guys, so I was looking through my videos today and I noticed that certain videos have almost no views. I understand that some videos will of course be more popular than others, but I didn't realize there would be such a huge difference. Example: I uploaded a video this morning and it's...

I wonder if there is a way to know what popular is these days. At the moment is Pokémon Go really popular and everyone is making video's about it. But is there a site or something where you can see some popular topics or something ?