Some MaxFun shows use Dynamic Ad Insertion (DAI), meaning ads are recorded separately from the episode and inserted into episodes whenever someone downloads a show. Creating an ad-free version of these shows just means telling a computer “hey, don’t insert ads into these episodes.” Pretty simple.
Other shows have "baked-in" ads, where the ads are edited directly into the show. For these shows, that means a producer would need to manually edit every single episode in the back catalogue in order to have those episodes be ad-free. That's not something we have the capacity to do right now, but we still wanted to be able to give the shows the option to have new episodes be ad-free. For shows with baked-in ads, you can still listen to all of the older episodes (before we started offering the ad-free option) in the original feed.