Candidates' Web Sites Get to Know the Voters

"Both campaigns are embracing online targeting ad technologies," said Michael Bassik, vice president of interactive marketing at MSHC Partners, a leading Democratic communications firm. "It sounds scarier, but it's less intrusive than direct mail ever was."

Guessing how a person might vote -- and whether they might be receptive to a pitch -- has long been part of the science of political marketing.

But the Internet creates many new ways for campaigns to gather data about potential voters, and then to reach out to them.

Both presidential campaigns are using "retargeting" to send ads to people who visited their Web sites but who didn't leave their name or e-mail address.

To track those visitors even after they've left, the site places a small file, known as a cookie, on the visitor's Web browser. When that person visits another site, an advertising system can send a tailored ad after detecting the cookie, which indicates that the person is a potential voter for the given candidate.

That's how the Obama campaign can send an ad to a person long after they've visited the Obama site, even when their mind is on something far afield from politics -- like Phelps and Beard.

The cookie might even indicate a user's interests, allowing the campaign to further tailor an ad. For example, looking at the cookies from McCain's site reveals that a person who visits looking for information about gas prices is tagged that way.

Using that information, the campaign could send the user an ad about McCain's energy policy.

"If you responded to a certain kind of ad, we could hit you with a similarly themed ad at another time," said Michael Palmer, the eCampaign director for McCain. "Without violating any privacy concerns, we try to know as much about our users as possible."

Identifying potential supporters is also increasingly easier with the Internet, because what a person reads or browses on the Internet can reveal their political leanings.

Specific Media, a company that has worked with both sides in the presidential race, combines data about users -- some of which it buys and some of which it receives from partners -- to create profiles on about 175 million people, according to the company's senior vice president David Jakubowski.

The data it collects includes information about what articles the person has read on some newspaper sites, what blogs and forums the person attends and what other sites are visited.