[nextn]

Use quadratic post fees. The larger the number of people who try to view a post, the larger the fee becomes or the post stops being viewable.

So the fee isn't a one-time fee, but an "open" fee that keeps increasing.

Another mechanism is to require a fee to view. If after viewing the content the user deems the content isn't valuable, they flag it in some way or they don't bookmark it, and this indicates the poster should pay the display fee.