I would wager that most people who aren't watching their bills closely enough to notice they haven't actually used their Netflix account in a year aren't very price sensitive. They have money they are, by revealed preferences, willing to throw into the pot, which lowers the service cost for everyone else who does actually use it. If anything one should be the least sympathetic to their plight, from a welfare angle.
The business model you're actually looking for is a utility, or a pay-per-use model. Getting charged per API endpoint hit, or by TCP packets sent, or something. A subscription service is explicitly designed to avoid all that, because our brains like nice round predicable numbers. Sophisticated users everywhere use this model, but most of us have better things to be sophisticated all the time.