Transcript for Presidential Campaigning: Getting to Know You
You subscribe to HBO. What kind of beer do you drink inquiring minds including the presidential campaigns want to know because of something called. Micro targeting this is the new frontier -- personalized campaigning it works by finding often baffling correlations between the stuff you like. And who you're likely to vote for here's ABC's John done. As -- tight election heads toward a photo finish in fifteen days. There are really two presidential campaigns taking place there's the one who saw tonight on the debate stage. It's also there in the TV ads in the big speeches. But then there is the other things -- -- here one where messages get tailored just for you and are delivered not in front of the TV cameras but right to your mailbox. The -- prediction the likelihood that you Oregon said the campaign can make sure that -- them when they're talking a gun rights are just sending its people that they are very likely and not sending that same message that we're not owning their neighbor -- Get something else get something not at all it is called micro targeting says -- Eisenberg author of the new book called the victory lap. You can have -- theoretically different -- and every person on a block. But in order to do that they have to figure out who you are and what's important to you. How'd they do that data truckloads of it in the modern world you are leaving trails of information about yourself everywhere you go. And the campaigns are buying it up. The use it to build a profile of you say you -- thirty rock and you drink Molson that -- probably a Democrat who votes frequently. If your beer of choice is -- Coors Light consumed while you're watching and CIS odds are you're -- loyal Republican. How much of this is about actually trying to change people's minds vs. Just trying to get people who would vote for you. To go vote on election this is the big change in the way campaigns -- in the last decade it's four lasts about just changing people's minds and far more about modifying their behavior. And guess what there's an app for that as -- showed me the other day the Obama campaign wants its supporters to knock on doors and get out the vote. But not just any doors in the campaign -- all the data they have about voters and -- these micro targeting algorithms to sort through they want their volunteers to talk to -- -- -- they want -- to interact with. Each of these flags represents one particular house an election year short -- to figuring out exactly who in this neighborhood is most likely to vote for their guy. So this is a real map of the street -- on yes. And -- and -- flags represent. Real houses -- houses like for instance whoever lives at this house which we're blurring a bit for privacy. The -- loose stuff about this person. What do we know. There's a -- through old woman. She's a registered Democrat and means with -- because -- -- begins with an arm. So if you're sitting at home tomorrow afternoon and there's a knock on the door and it's an Obama volunteer or -- -- here. They know something about -- -- knocking at your door they know a lot about Jill and they've made a whole lot of assumptions about so -- not at your door by accident not at all now we're we're way past that. -- which means campaign ads are popping up in the unlikeliest of places like these Obama ads inside video games one of the other variables Obama's campaign in 2000 realize is helping to predict support for him. Was the presence of a teenager a household. They went out and found video games for you can buy ads in the video games and bought early vote reminders and in this election there's no such thing as too narrow a niche in a mailer to homes in Northern Virginia where there is some Lyme Disease concerned. Romney told voters he's against it. So doesn't work. There's nothing to show definitely that these tactics put them over the finish line. Instead Eisenberg says. In the end the single most important piece of predictive data isn't what beer you drink but whether you're a registered Democrat or Republican. Which is publicly available on the voter rolls all the rest is extra. But it's a lot. -- it's like they've got the whole neighborhood they can see into the political soul. Peoples who even now sitting in their houses. And does that seem just a little creepy. They campaigns even though they know they have the tools to really target. Specific messages to voters are also -- that the cost of getting caught doing it if they contradict themselves -- high. In other words when they knock on your door. We're out here and just because they found -- doesn't mean you have to answer. John Donvan ABC news Washington.
This transcript has been automatically generated and may not be 100% accurate.