Metrics of popularity in Korea and their equivalents in Japan and China?

I'm sorry if this is in the wrong section.

So... as someone who stans the nation's IT girl Jennie, I like to think I know about the metrics of popularity in Korea.

• Brand reputation
• Naver trends
• Articles (+ views and reacts)
• Ranking high on polls

Among many other things. But I can't think of them all from the top of my head.

BUT the reason I made this thread was to ask what are the equivalents in Japan and China? How do we know who is the IT girl of those 2 countries?

Thank you loves!