Someone asked me to look this up, so I did a mini-research project. For a while I’ve assumed that online content contribution followed the 80/20 rule (the Pareto Principle) which maintains that for many things, 80% of the consequences stem from 20% of the causes– e.g. 20% of volunteers do 80% of the work.
However, for a while I’ve been suspicious of the Pew Internet & American Life project that 44% of internet users, and 57% of teen internet users, have contributed content. This is a totally unuseful number, since it makes no distinction between Joe Doe who writes a single IMDB review, and Jane Doe who uploads 10 YouTube vlogs a week. You can’t make product decisions on such a vague number.
I started with Jakob Nielsen, who claims that:
In most online communities, 90% of users are lurkers who never contribute, 9% of users contribute a little, and 1% of users account for almost all the action.
Does this hold up after running some numbers? Well, first of all, in order to determine what percentage of site visitors contribute content, we have to know the number of site visitors. I am far from convinced that most sites’ proprietary user stats are correct, as it’s in every site’s best interest to overstate their numbers, and MySpace, Yahoo, Wikipedia etc. don’t tend to be extremely forthcoming about whether they are talking about unique visitors, repeat visitors, user accounts, etc.
If we fiat that all site visitor statistics are correct, then Nielsen’s law appears to be accurate.
Wikipedia: Only about 1-2% of total site visitors contribute content, according to Yochai Benkler’s The Wealth of Networks. (As of 2005. See graph).
I think this number is underclaimed, but it’s true that there are a core number of Wiki contributors who do the bulk of the work of the site. Jimmy Wales has claimed that 10% of users make 80% of all edits, 5% of users make 66% of edits and 2.5% of users make half of all edits. (Source: [ppt, see Slide 25]).
– Youtube: YouTube is currently serving 100 million videos per day, with more than 65,000 videos being uploaded daily. (Numbers from YouTube). 65K is about 0.1% of 100 million. Of course, the number of videos being watched is not the same thing as the number of users. Even so, YouTube has approx 20M unique users per month. 65K * 30 = is 1,950,000 which is 9.75% of 20 million. But, again, we have no idea how many of these videos are uploaded by the same people.
Bradley Horowitz at Yahoo wrote a blog post called “Creators, Synthesizers and Consumers” in which he claims that about 1% of users create content, 10% “synthesize” content (add comments, etc.) and 100% of people benefit.
So let’s assume that he and Jakob are right: 1% hardcore contributors, 10% overall contributors and 90% total lurkers.
What impact does this have for feature design?
1. You don’t want all your users to contribute. The undereditorialization of YouTube already makes it difficult to find stuff you think is really good. If every user was spamming every social software site with mediocre content, the sites would lose value.
2. Not every user is created equal. Keep your contributors happy. Even if they are demanding, picky nerds.
3. On the other hand, contributors are only 10% of your overall users. Make your uploading and editing tools good, but make the browsing/searching stuff really really good.
I’d appreciate if anyone has any stats they could share to prove/disprove these numbers.