How do you compare artists?

[Accessing]

This sounds like a really silly question and conversation but I found myself in a situation where I want to compare two rappers together and argue which one is the biggest in terms of fame, money or songs. 

When I step back and think about it my biggest metric is monthly listeners but across multiple platforms that's kinda hard to judge by. Does anyone have a go to? Followers/following is a thing but I don't know if it really means as much since rappers have cult followings similar to celebrities that wouldn't equate to listens. 

[ADM S Osman]

Monthly listeners is probably the best available public metric. Monthly listeners is typically also related to how much an artist releases that is still being kept in rotation.