The jar There is a number that keeps coming up in online communities. Ninety percent. Ninety percent of members never post. Nine percent contribute occasionally. One percent create nearly everything everyone else reads. Usability researchers call it participation inequality, or the 90-9-1 rule, and it has been documented for decades across every kind of forum, group, and comment thread that exists. In most contexts, this is an interesting footnote. In rare disease, it means t