1% rule

The 1% rule is a rule of thumb pertaining to participation in an internet community, stating that only 1% of the users of a website actively create new content, while the other 99% of the participants only lurk. Variants include the 1-9-90 rule (sometimes 90–9–1 principle or the 89:10:1 ratio), which states that in a collaborative website such as a wiki, 90% of the participants of a community only view content, 9% of the participants edit content, and 1% of the participants actively create new content.