Barack Obama won re-election to a second term as the 44th president of the United States Tuesday night, with a campaign that was undergirded by disciplined digital effort that relied heavily on targeted voter communications, an ambitious ground game, and extensive and innovative use of social media and online fundraising tools.

Obama squeaked by with almost 50 percent of the nation's popular vote, and a 303-206 advantage in electoral votes Tuesday night, thanks to key victories in the battleground states Colorado, Florida, Ohio, Pennsylvania, Iowa, and Nevada.

President Obama's 2012 digital campaign as an incumbent was a much more top-down and meticulously organized affair than his more free-wheeling 2008 run against the political establishment, which had more of a barn-raising character to it both online and off.

This level of organization was largely enabled by the overhauling of the campaign's digital infrastructure, which manifested itself publicly in the form of Dashboard, its organizing software and smartphone canvassing app.

Unlike many of the often ad-hoc efforts of the 2008 campaign, the digital plumbing of the 2012 project was revamped so that intelligence was distributed. One side of the army knew what was happening on the other because the campaign's databases were integrated.

"One of the things from my understanding is that Dashboard creates integration across various universes of voters and volunteers across the campaign," said Daniel Kreiss, an assistant professor in the School of Journalism and Mass Communication at the University of North Carolina at Chapel Hill, and the author of "Taking Our Country Back: The Crafting of Networked Politics from Howard Dean to Barack Obama."

That matters because it enables the campaign to better direct its resources.

"The calls that you make, the door-to-door contacts that you make are immediately synched with the voter file, and all that data is aggregated across the various platforms that you're using to access Dashboard," Kreiss said. "In 2012 once you had that integration, you could actually have your online people making calls to those people who are a high priority, and that is a huge deal, and makes a huge difference."

That definitely seemed to be the case on Tuesday night when I logged into Dashboard. After greeting me with a message asking me whether I had voted or not, it then tried to get me to message all my friends on Facebook to go and vote. Then it directed me to call someone in Nevada to prod them to vote, complete with the address of their polling location.

"There was a lot more integration of datastreams than what they had in 2008," Kreiss said."In 2008, there were a lot of data silos. You would have your online volunteers making phone calls to a different universe of voters than the priorities of the field campaign."

Indeed, the Obama campaign expanded its efforts around local team-building in 2012, morphing its 2008 neighbor-to-neighbor tool to a neighborhood-focused team dashboard where volunteers could keep track of their contributions to the campaign in terms of the number and kind of campaigning activities they had taken on behalf of Obama. They were also able to track what other actions members of their local terms had taken.

These efforts apparently were in large part more efficiently channeled as a result of analysis by the team of data scientists and tech gurus that the campaign recruited to crunch through all the information that the campaign had gathered about voters through its volunteers, Facebook profiles and commercial databases.

To be sure, the digital operations were built around the campaign's strategy of keeping persuasion efforts local, in-person and propagated through personal relationships as much as possible, as Obama's Campaign Manager Jim Messina explained during the ABC/Yahoo News forum at the Democratic National Convention in September. The campaign opened twice as many field offices as Mitt Romney's campaign in swing states, and top campaign staffers emphasized the neighborhood-focused aspect of the campaign during the Democratic National convention this summer.

But President Obama also made strategic use of social media. On Tuesday evening, for example, the president took to Reddit, the self-proclaimed front page of the Internet, to urge Redditors in their own language to get out the vote:

"I'm checking in because polls will start closing in this election in just a few hours, and I need you to vote. Millions of Americans have stepped up in support of this campaign over the last 19 months, and today we decide what the next four years look like -- but only if we show up. I ask that you go out there and cast your vote, whatever your political persuasion. You can confirm your polling location here: https://www.barackobama.com/lookup

If you’ve voted already, don't stop there -- spread the word to your friends, roommates, and neighbors. Think of it as upvoting.

That last-minute pitch was a strategically-timed follow-up to his surprise August appearance on Reddit, when Obama participated in the first-ever presidential Ask-Me- Anything session with Redditors, which generated plenty of earned media mentions. Obama also used social media to great effect in January, when he held a live Google+ Hangout with five voters across the country.

Another innovation this time around was the campaign's effort to channel the volunteer support of the Bay Area's tech talent with a tech field office in San Francisco, managed by Community Outreach Lead Catherine Bracy and former lead YouTube developer Angus Durocher. That project yielded projects such as this data visualization project, and this ride-share project. The Bay Area also sprouted a Tech4Obama group, which grew to become a nationwide volunteer and fundraising group that helped raise an estimated $26 million for Obama and built a social media reach of more than 5 million people.

The 2012 campaign also saw a number of important fundraising innovations.

In January, for example, the campaign started to use the mobile credit card reading system Square to process campaign donations at campaign events. Then in May, Obama's digital agency Blue State Digital announced its new "Quick Donate" system, which enabled supporters to donate via their mobile phones after they completed a one-time sign up process to store their credit card information. After signing up, supporters could respond to a link in a text message or email and donate through a Web form. Then in August, the campaign announced that it was enabling donations directly through text messages.

The campaign also used its data on members of its e-mail list to pressure them to donate. In a November 1 e-mail message, for example, Messina e-mailed me to tell me that: "According to our records associated with this exact email address, you haven't given to this campaign yet." That was just one of several e-mails telling me that the Obama campaign was keeping score. In all, more than four million people donated to the campaign, according to campaign e-mails to list subscribers (For context, as of 2008, the campaign had a list of 13 million subscribers.)

Other than planning Obama's strategic appearances on Google+ and Reddit, the campaign also made extensive use of online video for persuasion.

In an unprecedented move, for example, the campaign commissioned a 17-minute online ad from documentary filmmaker Davis Guggenheim that recapped the Administration's view of its accomplishments in its first term.

The campaign released the spot in March and streamed it "live," focusing the media's attention and national discussion about the piece. The campaign also used video extensively to tout the impact of the Obama Administration's landmark legislative efforts such as the Affordable Care Act. And the campaign's list subscribers would often find videos of Deputy Campaign Manager Stephanie Cutter in their inboxes refuting the latest Romney attack ad, or pitching an infographic to make a point about how Obama's policies have improved the employment picture in the United States.

On Tuesday, Cutter's final video exhortation was a humorous get-out-the-vote video, castigating watchers for being there, yet asking them to take specific actions to direct their friends to go out to vote, and to make calls to get out the vote.

"Hi, I'm Stephanie Cutter, deputy campaign manager for Obama for America, and what are you doing watching this video?" she asked. "Times up! It's Election Day, go vote."