HARI SREENIVASAN: Here in Columbus, Ohio, both candidates are fighting hard. I'm going to visit President Obama's campaign first. He has got digital teams across the country, but the one he has in Ohio is one of his largest.
WOMAN: Let's just do a check. E-mail, I just sent to the thread. Landing page, done.
HARI SREENIVASAN: This may look like a traditional campaign team doing traditional field work, but they're part of a campaign that's collected more voter data than any other in history. And their volunteers are using a slew of new tools for both data gathering and voter targeting.
The GPS in your smartphone is the blue dot in the center.
I'm meeting with the digital director for Ohio, Ashley Bryant, a key player in one of the most data-hungry campaigns in history.
ASHLEY BRYANT, Obama Campaign: These flags are the voters. These are the doors that you could potentially knock.
HARI SREENIVASAN: Now anyone who signs up for the campaign online can download the Obama app that comes pre-loaded with targets and tailored scripts. And they're not just pitching President Obama. They're also collecting even more information.
ASHLEY BRYANT: Who do you support for president? And we simply click that button, now whether they're a strong supporter, a lean supporter, if they're a strong Republican. Once that information is there, it's able to be, you know, researched and analyzed and figure out what are the buckets?
HARI SREENIVASAN: That's right, buckets. For both the Romney and Obama campaigns, the goal is to target voters efficiently, so they divide us into groups called buckets, the mobilization bucket for strong supporters of the candidate, the opposition bucket for those voting for the other guy, so no need to spend resources on them, and the persuasion bucket for those valuable undecideds.
And the campaigns create buckets within buckets. The more data they have, the more they can refine them.
So, details, notes. If that person tells me what their most important issue is, do I put that in the notes somewhere?
ASHLEY BRYANT: I would absolutely put that in the notes, because we know next time when we're building an audience that, you know, Joe Schmoe was a small business owner. So, you want to absolutely make sure that he's a part of that audience.
HARI SREENIVASAN: And the campaign collects even more data through a new organizing tool called Dashboard, which allows them to pinpoint not just potential voters, but potential volunteers, the people in the mobilization bucket.
ASHLEY BRYANT: This is our online field office. And so Dashboard is definitely both a social tool, but also a reporting tool, a team-building tool. Everything you can think that we're doing offline, we're trying to bring that onto the online space.
Very simple initial sign-up is going to be your street address, your zip code and tell us the issues that most matter to you and things like that. And so here, this also gives you the option of logging in with Facebook. It's a lot easier because Facebook already has a lot of your information, whether it's phone number, address, et cetera.
HARI SREENIVASAN: Not to mention who your friends are, your interests and hobbies and anything else in your public profile.
With all that information, the campaign is able to build teams of like-minded volunteers, Latinos for Obama, Pacific Islanders for Obama, sportsmen for Obama, all being recruited as part of the Obama ground game. They meet online and then gather in the real world.
WOMAN: I think we're expecting a few more people, but we are going to get started, so we can keep on with our agenda.
HARI SREENIVASAN: The day we were at the Columbus field office, this group of volunteers who cared about lesbian, gay, bisexual and transgender issues was preparing to go out and canvass local voters in support of the president.
It seems that whether it's Dashboard or the mobile app, they kind of serve two purposes, one, to make sure your teams are in communication with one another, and, another, to kind of learn about the voters that you're going out and reaching.
ASHLEY BRYANT: Oh, absolutely. We're always going to be collecting information, because that's how, you know, we extend our reach. And that's how we can continue to communicate with that person. Just one phone call or one e-mail is not going to get that person to the polls on Election Day.
HARI SREENIVASAN: For years, campaigns have dreamed of being able to take the information they gather through canvassing and phone banking, social media and e-mail groups and match it to our voter files and the data culled by private commercial data brokers to create an enormous unified database of voter information.
This year, for the first time ever, the campaigns have that ability.
ASHLEY BRYANT: Now we're at a place where, whether you're a field person entering their numbers in, in the evening from us collecting information from a Facebook post, if you're in Virginia, if you're in Ohio, that's all going to filter into this one platform that not only our states can see, but our headquarters can see as well.
HARI SREENIVASAN: So, with access to an unprecedented wealth of data, the campaigns can send an issue-related video ad to someone in the persuasion bucket.
PRESIDENT BARACK OBAMA: It's time for a new economic patriotism.
HARI SREENIVASAN: Or send canvassers to solicit donations from someone in the mobilization bucket.
WOMAN: Fired up!
VOLUNTEERS: Ready to go!
WOMAN: Fired up!
VOLUNTEERS: Ready to go!
HARI SREENIVASAN: It all adds up to a formidable digital army. Plus, President Obama has got a four-year head-start and more than three times as many Ohio field offices as Mitt Romney.
But the digital battlefield has no boundary. To see how Romney's fighting for Ohio, I need to go 700 miles east to campaign headquarters in Boston.
Zac Moffatt is Romney's digital director.
Essentially, the Obama has had that significant head-start. So, how do you deal with that challenge?
ZAC MOFFATT, Romney Campaign: We don't judge ourselves based upon the Obama campaign, because, if we did, we would be judging ourselves against an entity that has been around for six years and who has run unopposed for the last three.
For the Romney campaign, we have determined that if we only rely on national television, we will lose this election.
HARI SREENIVASAN: Last year, Moffatt co-commissioned a survey that found roughly one-third of the electorate is more difficult to reach by traditional campaign methods. They're the people who spend more of their lives online. Moffatt calls these voters off the grid.
This large off-the-grid population, who are they?
ZAC MOFFATT: We define them by this term of people who don't watch live television anymore. Other than sports, they kind of -- they choose to live their lives on demand.
So, what they do is they primarily watch DVR, Hulu, Netflix. They're choosing when they consume their content. So, that's the big differential. It's an astronomical amount of people who do not see a TV spot, one in three voters.
HARI SREENIVASAN: That works out to over two million off-the-grid voters in Ohio alone, more than enough to swing the presidential election.
So, if off-the-grid voters won't come to the ads, the ads will have to come to them. The campaigns find them by following the trail of cookie crumbs. So, what's a cookie? Well, a cookie is an invisible piece of code that gets dropped onto your computer when you visit a Web site. They're there to help companies and advertisers track your movements and learn more about you.
Do you click FOX News or CNN? Huffington Post or Drudge Report? Shop for a Hummer or a Prius? The cookies on your commuter record it all. It's valuable information for anyone who wants to sell you something, including a presidential candidate.
This year's election is the first time the presidential campaigns have been able to take this online cookie data and match it with your voter information, social networks and the kind of consumer data gathered by private commercial data brokers.
The result is the clearest, most detailed picture of the electorate the campaigns have ever had, though they'd rather you didn't think about that too much.
If you have all these different data points, aren't you almost getting to me? So, let's say if you said off-the-gridder that's independent in Virginia that might be in the Indian-American subcommunity, you're getting closer and closer and closer to figuring out who I am, right?
ZAC MOFFATT: It's not imperative and it's not something we strive as a campaign to know it's you. And whereas mail, when it comes to your house, it has your name on it, right?
HARI SREENIVASAN: Right.
ZAC MOFFATT: Very, very different experience than what is occurring online. You would never get an ad unit sent to you with your name in it, because I think that that would be -- people would feel very, very uncomfortable with that at this stage of kind of the digital privacy evolution.
HARI SREENIVASAN: Once Moffatt has his list of targets, he sends it to a company he co-founded, an interactive ad agency called Targeted Victory.
MICHAEL BEACH, Targeted Victory: Conservative. Conservative. Conservative. Conservative. Conservative.
HARI SREENIVASAN: Its other co-founder, Michael Beach, and his team of digital detectives follow our online footprints and help Moffatt find key targets like the off-the-gridders. Beach gave me a glimpse of how he does it.
MICHAEL BEACH: Think of it less that we're buying a channel, or -- that we're buying an audience. And so we're not necessarily concerned with where the ad runs as to who it runs to. And that kind of really flips the whole kind of mass marketing, you know, tradition on its head.
HARI SREENIVASAN: Political operatives had to where to find their most valuable targets. Today, they have a treasure map that leads right to them.
Now, remember cookies, those little pieces of code that can be dropped on your browser to record what you do online? Campaigns aren't only buying ads on specific websites. They're also buying access to your cookies, which tell the campaigns where you go online. This lets them follow you around the Internet and hit you with their advertising on whatever websites you visit.
And because the campaigns have so much information about us, they can target their ads so specifically that different people in the same household may see totally different ads. And they can measure instantaneously whether the ad hits it target, something television-based campaigns can only dream of.
So, unlike a traditional TV purchase, there's a huge opportunity here for you to learn about me on whether I see the ad, whether I interact with the ad or engage with the ad?
MICHAEL BEACH: Anything like that is feedback that tells the campaign this is the right message or this is not the right message. And so that could change, you know, what a campaign decided to deliver in the future.
HARI SREENIVASAN: It's an endless feedback loop channeling data back to the campaigns for them to learn even more about us and refine their pitches further.
It's the campaign strategy of the future.
Spending on online ads in this year's election is projected to reach $160 million. That's a sixfold increase since 2008. And as we live more and more of our lives online, the importance of the digital campaign will only grow.
On Nov. 6, the election will be over, and the planning for 2016 will begin. Campaigns will come and go every four years, but our data and the digital feedback loop will live on.