Comment by heynk

I'm not in the podcast industry, but I'd listen to this episode of Darknet Diaries:

https://darknetdiaries.com/episode/27/

He dives into "podcast promoters" that are pretty effective at getting into the top charts. I mention this not because I think you should use these services, but because he actually gets some evidence around what the charts are based off of.

It's also a great podcast in general.