I think most shows send 95% of the Boost to the artist while their tracks are playing. The funny thing is that the part they keep is so they see the Boost coming in and can thank people in the next episode. 

When the host is talking, they get the sats and when the song is playing the artist get the sats.

This is all open and transparent so you can check to see where the sats are going when you Boost. Most apps show the splits in one way or another, but my favorite is Podverse on mobile because the Boost button even turns green when the show switches to an artist wallet.