People involved in Obama for America's digital and technology operations say one of the biggest takeaways from the 2012 campaign is the success of a new kind of peer-to-peer digital persuasion tool referred to internally as "targeted sharing."

Well before the campaign reached fever pitch, OfA chief data scientist Rayid Ghani and analyst Matt Rattigan brought the technology team a prototype piece of software. The prototype used a script to check a given supporter's Facebook friends list against what the campaign knew about those friends. The campaign could use the merged data to create arbitrary scores that indicated which of a user's Facebook friends the campaign would like to present with a given piece of content. Obama for America could use it over and over again to make it more likely that people fitting certain profiles would be likely to see content targeted to them spilling into their newsfeeds, from the campaign, through their friends' Facebook posts.

By the end of 2011, the campaign had already decided what approach to existing voter turnout or new voter registration it needed in order to win each swing state. Obama for America planned digital campaigns based on what it needed to accomplish whatever the task at hand would be. For example, those above-the-fold ad buys on the front page of the the Milwaukee Journal-Sentinel's or Columbus Dispatch's websites to drive the early voting that the campaign believed was crucial to victory in Wisconsin and Ohio. People in techPresident headquarters in New York saw advertisements on NYTimes.com that were most likely intended to convert viewers into donors. The prototype produced by Ghani and Rattigan would allow OfA Digital to be far more precise about what kind of content they were asking supporters to share around the web as well.

The only problem was that the prototype could not work at the necessary scale. Ghani and Rattigan's script took 45 minutes to run per person — not nearly fast enough. But anyone who opted to use Facebook single sign-on for an Obama for America web property was prompted to authorize the OfA Facebook application to connect to their account. Single sign-on users also gave OfA permission to glean all the data it needed to decide which content that user should be asked to share and guess who that user should share it with. In part because it linked the two, OfA was able to build up a user base of nearly 1 million people for its Facebook app by election day — making the potential gains for targeted sharing well worth some time and effort.

OfA developers went to work, and by midsummer the tech team had targeted sharing working in production and in real time.

By the end of the campaign, says Obama for America analytics chief Dan Wagner, the click-through rate on a targeted share was more than twice as high as the rate for a banner ad. Thanks to a convergence of three different teams — analytics, digital, and tech — the campaign had developed a tool that staff believe delivered empirically higher results for the re-elect using social media. In a campaign year full of hype and flashy social media toys, that's a big, bold claim.

Applying the same principles to get out the vote, Obama for America asked its supporters who had been signed up for the OfA Facebook application to pick potential voters from among their friends in swing states and urge them to get to the ballot box or register to vote. In the final days before the election and on election day, the application flooded its users with notifications asking them to reach out on the campaign's behalf. Officials told Time's Michael Scherer that a staggering 20 percent of people asked by their friends to register, vote or take another activity went ahead and did it. While the campaign hasn't shared how many people elected to press the case for Obama on Facebook in this way, and this is only remarkable if enough people participated to help close the distance for OfA in voter registrations and turnout where it had those goals, the success rate is high enough to raise eyebrows. Behind the Facebook application driving get out the vote was the same targeted sharing code.

Targeted sharing was for more than just Facebook, too. Tech team member Will St. Clair, who worked on the code, says that it was a piece of back-end infrastructure. The piece he worked on retrieved those voter scores and made them available to different departments — any department — so it could be used to inform a targeted email, too, for example.

It's unclear what happens next for this code or any of the other innovations built in-house for the Obama campaign. Democrats now seem to be weighing the cost of keeping some aspects of their new codebase maintained and functional against its potential utility in the election cycles to come. The software belongs to Obama for America, and could, in theory, be transferred to the Democratic National Committee, as OfA's email list was moved to Organizing for America after 2008 and made part of the DNC.