I've found the 90-9-1 rule to be strikingly true online and, if anything, optimistic in the percentage of the audience which are regular posters. And that's just for a very basic interactive activity like posting comments. The percentages drop steeply as you get into interactive functions that require more time and effort, like filling out profiles or writing reviews. I took a stab at setting interactivity expectations here, based on what we learned at TechRepublic with some flamingly unsuccessful blog, profile, and social bookmarking projects. I can say with a straight face that getting a decent user-submitted video is literally a one-in-a-million proposition.
The vast majority of YouTube's initial users didn't give a crap about making viral videos or monetizing video content, they just wanted an easy way to format videos and post them online. Almost all Flickr users don't care about aggregated group feeds or discovering like-minded photogs via tags, they just want an easy way to post and store pictures online. Flickr and YouTube have value to me even if I'm the only guy using them. All those group-dependent features are a result of Flickr and YouTube's scale. You can't start with those features, you tack them on once you're massive.
Moral: Any feature spec that includes the phrase "will be useful once a bunch of people join in" will almost certainly fail because there is no value for the initial users.
That upvoting feature that works just like Reddit? They'll use actual Reddit instead. Your blog platform? If they wanted to blog, they'd use WordPress, Blogger, or any of the other services out there first. A user profile? Maybe you've heard of Facebook. Until you reach the stratospheric heights of traffic, there's no point in trying to create new user behaviors on your site. The best thing you can do is reinforce the existing user behaviors. If they came to you for content, the best thing you can do is show them more content. If they came here looking for help making a buying decision, help them make a buying decision.
Moral: Any feature spec that includes the phrase "if we can just get the users to do X" will fail, because if they aren't doing X already, they aren't likely to start.
[This post was originally published on Jan. 18, 2010.]