From a Wired article (this makes me laugh):
not that anyone has read the
terms of service, but it does specify that your account “may not be shared with individuals beyond your household”—it’s also true that sharing user names and passwords with even your closest relations can have woesome consequences.
Uh, setup a specific, and singular credentialed account for Netflix then you dip shits. The only thing you will end sharing is a user / pass that is only good for Netflix.
Here's a thought: Sell the service by the # of concurrent streams period. That is I sign up and initially subscribe to X # of streams and then give me the ability to pick stream one and if I want assign a user/pass to it. Rinse and repeat for the others. Just like their profiles work.
The household provision is an artificial construct. X # of streams is simply X # of streams at that point. Easy enough to prevent an account from multiple logins then. Or if you keep your streams under a single user/pass then you can only have X amount of concurrent logins.