For new registrations, they tracK 3 things you need to make sure are unique and nobody else in your house has already used:
IP, email and phone number, and all must be unique!
To fix up each I suggest:
IP, use a VPN
email - create a new one, and change it later? (not sure this feature exists yet, but you can forward email to main
phone - use a phone texting site (that hosts numbers and allows you to receive a text message on the web page), and when they text you for confirmation number, it will show up on a shared page, others will only see your confirmation number, nothing else about you..
It should be obvious when you fail to register because of one of the above issues, but it's not.. you just never get approved.
Yes, we considered the identity issues and did make sure we completely separated mine - and in the meantime had friends who had multiple people in a household sign up without a hitch. What's ironic is that we do have two people interested in posting separate unique content but somehow couldn't get both onto the platform.