On Twitter, Followers Aren’t Really Friends

This past weekend, we had yet another tempest in a teapot here in the blogosphere, this time over what, exactly, determines the authority of a tweet on Twitter. Some argued that the number of followers is the best yardstick with which to measure how important a tweet was, while others argued that it is who you follow that's more valuable. The high drama made me wonder: Why can't a tweet just be a tweet? Why does it have to be about authority? (I assume authority means "power to influence or command thought, opinion or behavior.") Nevertheless the discussion reminded me of a recent conversation I had with Bernardo Huberman, director of HP's Social Computing Lab. He (along with Daniel M. Romero and Fang Wu) recently collected and analyzed information from the Twitter network to find out which people truly matter in an individual's social graph – and what ultimately influences a person's ability to absorb content. For each user of Twitter in our data set we obtained the number of followers and followees (people followed by a user) the user has declared, along with the content and date stamp of all his posts. Our data set consisted of a total of 309,740 users, who on average posted 255 posts, had 85 followers, and followed 80 other users. Among the 309,740 users only 211,024 posted at least twice. We call them the active users. We also define the active time of an active user by the time that has elapsed between his first and last post. On average, active users were active for 206 days. Huberman explained that in these time-constrained modern times, our relationships can be measured by the attention we accord to people. We do so by interacting with them — whether by making phone calls, meeting them for coffee, writing on their Facebook wall or in the case of Twitter, sending either direct or indirect replies. Interactions define the social relationship. On Twitter, he found that regardless of the number of followers or followees, there were very few friends in a personal Twitter circle. He used a very weak definition of "friend" — anyone to whom a user has directed a post at least twice. And because of that, Huberman says that in order to "influence a person's absorption of content, there is a need to find the hidden social network; the one that matters when trying to rely on word of mouth to spread an idea, a belief, or a trend." Huberman's study found that: Users with a large number of followers are not necessarily those with very large number of total posts. Even though the number of friends initially increases as the number of followees increases, after a while the number of friends starts to saturate and stays nearly constant. The number of people a user actually communicates with eventually stops increasing while the number of followees can continue to grow indefinitely.