So. I've been having one of my periodic mini-binges of the 'This American Life' podcast and they love a "so." There's a good one in the intro here (once you get past the 30 second ad at the beginning):
https://www.thisamericanlife.org/761/the-trojan-horse-affair
Here, I think "
so" is used to create the impression that we're just picking up where we left off at the end of the last instalment. It's like Ira Glass (the host of the podcast) and me had been having a really juicy chat in the kitchen at a party before someone wandered in and interrupted, and we've have to wait for them to leave before we can resume the discussion: "
So, now it's just us again, where were we?" That kind of "
so" works perfectly with the intimate nature of the radio or a podcast where it's just someone talking directly to you in your ear, and maybe when it's used by a contestant on a game show or wherever, it's a subconscious/nervous attempt to recreate that casual intimacy, that chumminess, in a more public setting?