As I write this post Twitter is rolling out lists.  If you are not yet familiar with twitter lists they are basically a way to categorize people into logical groups based on your own perceptions and the way you use Twitter.  A list can be private or public and, if public, others can see them and can add users to their own lists directly from them.  This seems like pretty simple and basic functionality, but I tell you it will create a fundamental change in the functionality of twitter and the value that users will get from it.

Robert Scoble (@scobleizer) has written an excellent post that outlines all of the features of lists and makes some conclusions about them.  Robert is a power user and I think some of his conclusions are biased by his particular use case scenario,  but in general Robert is spot on in saying “(twitter lists are) brilliant because it instantly made Twitter much more usable and interesting again”

While this is true, I think it will have some other interesting repercussions:

Ease of Adoption

Lists are curated by individuals.  Each member of a list has been hand selected by the list creator for the value they contribute.  Services like Listorious that make finding lists easier have already launched.  One reason that it takes a while “to get” Twitter is that it takes time find people who bring value to your Twitter experience and, in turn, cultivate a Twitter community.  Lists destroy this barrier to entry; from day one you can easily find a list or multiple lists of people with similar interests or experts in a field.  If you your interested in the stock market you can follow @stocktwit’s suggested list, if you like to cook follow @ZagetBuzz’s celebrity chefs list.  Immediately the content you see will be demonstrative of the greater value that you will gain form twitter as you begin to interact and cultivate your own twitter community.

Lists make the utility of twitter much greater for the casual user who can identify a few highly curated lists and simply follow the list stream rather than the people.  Once Tweetdeck, Seesmic and others Twitter clients integrate lists into their apps you will likely be able to view individual lists as columns in the application.  In this scenario it makes sense that “follower” growth rates will decline. After all why should I curate a list of "Influential in Tech" when Robert Scoble has done it for me; or “Thought Leaders” when Josh Weinberger has done it for me!

Taking lists and Making Them Your Own

Eventually people will realize that they need to cultivate their own lists.  This could be done by starting from scratch or starting from an existing list created by someone else.  One reason to make lists your own is that if you follow and rely on someone else’s list, and the creator deletes it – It’s gone!  Or if they delete or add someone, then you are subject the change.

It’s very likely that Twitter clients will soon make it easy to copy other peoples lists and will make it possible for you to convert your existing groups that you created in their native applications into twitter lists and vice versa.  In a recent conversation with Loic LeMeur (@loic) CEO of Seesmic, told me that they already have the API that enables them to incorporate lists into their client and web application, and Iain Doddsworth (@iaindoddsworth) of Tweetdeck, in response to my tweet “Wishing I could take Tweetdeck columns and convert them to Twitterlists with one click”, hinted to the same when he responded “watch this space”.   Already Dabr and TalkinPuffin have integrated lists into their Twitter clients. Until this is done effectively, it is really very difficult to use list and get value from them, unless you have a very specific purpose and the list is topically on point for your purpose.

Once you can see lists in columns in these clients the efficiency and productivity will be greatly increased, especially if you are able to change the constituents of the group directly from within the client.  True to Twitters nature they implemented a core feature and have left it to 3rd party developers to innovate.  This is a huge opportunity for Twitter clients and the Twitter client that best implements lists will be deeply loved.

Power and Influence

So what does this really mean to social structures within Twitter?

The act of creating lists may result in a dual class of Twitizen – Those who are on lists of influential people and those who are not.  To some extent lists may freeze the status quo of power structures within Twitter as they exist today, giving those with influence even more, while making it much harder for new users to be discovered and may hinder engagement by the long tale of users.

Lists are quickly becoming unwieldy and it takes a lot of effort to create and curate a list.  Anyone can create a list, but it is likely that the lists created by already influential people will be those lists most quickly adopted.  These widely followed lists will either be followed directly or used as the core to create one’s own list.  Either way, those who are on these lists will gain additional reach (one basic measurement of influence), while those who have not made the cut will have a difficult time being heard and their value will be lost in the background.

Everyone can see how many lists a person is on and people’s perception of each other will naturally be influenced by the quantity of lists that someone is on; this will become a default measure of their value.  Listorious is already ranking lists by number of followers.  This further amplifies the perception that quantity of followers a list has represents quality of the list itself.  This perception makes it more likely that the individual members of the list will be followed and amplifies their reach and influence.

The number of followers someone has, and the number of lists one is on, are both poor measures of influence for the simple reason that influence resides in context to presumed expertise – their domain of influence.  There are domains of influence in which a person could be extremely influential and other domains of influence where they may have very little influence at all.  Let’s take Barack Obama, he would have a huge influence if he were to say that there is a raised security threat and that Americans should not fly, but comparatively little influence if he were to say that kids should be careful of what they post on Facebook.  He is influential in the domain of national security and not so much in the domain of social matters of children.

In a perfect world, lists are a much better measure of influence than the number of followers that someone has, but just like follower counts have been gamed, so will lists.  In the near future you will see automated systems for reciprocal listing.  Also people will reciprocate as a social courtesy.

Still many people will create great lists, and these great lists will make it easier for people to gain value from their Twitter experience.  The problem is that many people will be overwhelmed by the sheer number of lists and will likely use the number of people who follow a given list as the measure of the quality of the list itself, where it is more accurately a measure of the popularity and/or influence of the list creator, or the result of first mover advantage.  This means that many great lists will go largely unnoticed.

Regardless of their imperfections, Twitter lists are a significant step forward.  While they are an imperfect measure of influence, in general they could be a great indicator for you to evaluate how and to whom you add value.  This is especially true if you have not yet created lists of your own, so the lists you are on are free from the influence of reciprocal listing.

My hope is that Twitter Lists are used by most people as a mechanism to discover new people to follow and they actively use the feature to create at least some of their own lists from scratch.  This would certainly make twitter more effective for many,  but I suspect that  many casual users will simply follow existing lists and only a serious few will take the time an effort to cultivate their own, in this scenario power differentials expand.

To be perfectly clear, I think list are great despite their imperfections and am deeply honored and humbled by all those who have put me on their lists, and I am glad that I have been able to add value.

I would love to hear your thoughts and impressions of lists and encourage your comments, or just tweet me @andrewmueller if you’d like to discuss it.

For some suggested etiquette and strategies for using lists you might want to check out Liz Pullens Twitter list 101 post

Update: 11/1/09 According to Techcrunch, Twitter Client Seesmic become the first major Twitter client to integrate lists, Tweetdeck will soon follow. You can find out more about this here.

[Editor’s Note: This article has been cross posted on http://www.muellerandrew.com/ visit for more information about the author. –mrh]