Estimate time to clear podcast backlog.
A podcast backlog is a queue with an arrival rate and a service rate, so the only figure that matters is the difference between them. Playback speed raises the service rate by dividing episode length, while every subscription adds to the arrival rate. If new episodes arrive faster than you finish them the backlog never clears no matter how long you listen, which is why the net rate is reported explicitly.
Service rate
Episodes per day = daily listening minutes / (episode length / playback speed)
Net queue change
Net per day = episodes cleared per day - new episodes per week / 7; days to clear = backlog / net per day
Because arrivals exceed throughput. Six new episodes a week is about 0.86 a day, so if you only finish 0.8 a day the pile grows regardless of effort. Unsubscribing is more effective than listening harder.
For news and topical shows, almost always — their value decays. Evergreen interview shows are the ones worth keeping in the queue.