I feel like it's not uncommon to see stories on hn that basically say we should do the opposite with our products. That is, charge more, because the difference between increased revenue vs. customers lost will still result in a net gain.
Now, obviously Louis CK is a pretty widely-known comedian who already probably has a lot of money, so I don't think he conducted this experiment as a way of becoming that much wealthier, and I applaud him for not taking advantage of his fans. If he had sold it for $20 and billed it as "cutting out the middle man" I'd wager his total revenue probably would have been higher, but he chose to cut his fans a better (for them) deal.
That said, for lesser-known folks with smaller audiences who aren't already wealthy enough to cut their fans some slack, I'd imagine they'd do better charging $20 rather than $5.