Pinterest is a Categorized Stream

I found Elad Gil’s recent post about Pinterest and the general trend toward curation quite interesting and insightful. However, I think this point is a bit off the mark:

All of the social services continued to serve content as a time ordered stream.  Moving from a stream to a structured collectible set of content was the next innovation in social media.

Pinterest boards provide structure, but they are still a stream that has a concept of time. They are not a “set” that is fixed in time. This distinction is important, and I think Pinterest (and most of the other curation sites) made the right decision to stick with a time-based stream rather than a static set.

The problem with a static collection that builds over time is that it gets stale. The Facebook friend list is one example (as Michael Arrington recently blogged). When I first joined just before coming to college, every person I met and friended was relevant and fresh. The total value of my Facebook network was high and rising fast. Over time, the value was brought up as I accumulated more friends, but brought down as I lost touch with some of my early friends and as the audience for my content became more varied. At some point the total value peaks and starts declining, and then I have to either remove friends or start over.

The stream model that’s worked so well for blogs, Facebook posts, and Twitter avoids this problem because the time aspect makes it very easy to tell what is fresh from what is stale. Old content doesn’t bog down the new content because it’s out of sight unless you look for it.

Pinterest, Quora’s Boards, and Snip.It follow the same model. On the Pinterest front page, pins are sorted most-recent first (left-to-right, then top-to-bottom). The same is true on an individual board’s page. This means curators can continually add content and the collection never feels stale because the newest content is always the most visible.

I’m going to label this class of product the categorized stream. A categorized stream is simply a stream with a name, like Places I want to go on Pinterest or Economics of Sports on Quora. Categorized streams are not entirely new: we’ve seen this before with tagged blog posts (Blogger) and bookmarks (, and to some extent twitter hashtags.

A categorized stream provides:

  • Built-in context for every post. On Facebook, the context is just “me”. On Pinterest, the context is “me + Places I want to go”. Every post automatically has more meaning and requires less explanation.
  • Consumer-side filtering. You can follow just the boards you like on Pinterest instead of every board of every friend; following someone’s board on Quora just follows that board. This is a different approach to the problem Google+ is trying to solve with Circles and Facebook is trying to solve with Friend Lists. It’s consumer-side filtering based on interests instead of producer-side filtering based on privacy. And that allows me, as a content creator or curator, to post content that appeals to only a subset of my connections without worrying about spamming the rest.

I think these effects, especially the second, could end up being as important to curation as the push-button element.

It will be very interesting to see how the curation sites evolve over the next year and if we start to see categorized streams cropping up elsewhere, in longer-form content than pure curation–perhaps on Google+, Facebook, or Twitter as they work to solve the relevancy problem. How would it change my Twitter experience if I could subscribe to @parislemon’s posts about tech but not to his posts about football?

Many thanks to Alison Johnston for reviewing drafts of this post.

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