The problems with per-watch pricing most come down to requiring a conscious decision each time they use your service, when you'd prefer that they be indifferent at most margins so that they don't have to be regularly reminded that oh, yeah, the amount of money they're spending on this darn this thing actually varies with how they use it.
Largely this breaks down into two salient factors:
- the friction of the transaction itself, which you largely shed when the consumer already has already agreed to be billed on usage, and
- metering aversion, which can be alleviated with a wide range of cheap tricks, e.g. using very coarse quantization: think not "rent this episode for just $0.99", but "rent up to 50 episodes this month for just $9.99". But the extreme of this is what you actually see: one price for any usage of the service at all, which ... is a popular pricing model at consumer scales because it works?
Give it a reasonable enough price (0.99 per episode is too expensive) and add a monthly cap (can be a bit higher than the current subscription) and you've got me as a customer.