Here's a tip: Don't add users until you're ready to share a post in Notable. Lots of Notable users love to add new people to their account before they have anything to share. This is similar to inviting someone to dinner and not preparing any food. Your guests are bound to be confused. Not to mention hungry.
It's the same concept in Notable: The person invited to an account can't see anything unless a particular Notable post or set is specifically shared with them. What ends up happening is that the newly invited user expects to be able to respond to something shared with them right away, but there's nothing there for them to look at. This can cause frustration and make them less likely to respond to sharing invites in the future. As a rule &mdash try not to invite anybody unless you have a screenshot of a website with notes on it that you want to share with them.