For several years, there has been a rule-of-thumb, called “90-9-1″, that 90% of online participation in groups/community consists of “lurkers” or more politely, “passive participants”, and only 1% are active creators. Jacob Nielsen’s 2006 post on Participation Inequality provides a good overview of this phenomenon.
All large-scale, multi-user communities and online social networks that rely on users to contribute content or build services share one property: most users don’t participate very much. Often, they simply lurk in the background.
In contrast, a tiny minority of users usually accounts for a disproportionately large amount of the content and other system activity.
A recent BBC survey of 7,500 people shows significantly different results.

Here we see that passive lurkers make up only 23% of participants; active (intense) participants have increased to 17%; and there is now an “Easy” group in the middle who, “ … respond largely to the activity of others. This includes replying, ‘liking’ and rating, all activities where there’s little effort, exposure ...