Online Data Helping Campaigns Customize Ads

Political campaigns, which have borrowed tricks from Madison Avenue for decades, are now fully engaged on the latest technological frontier in advertising: aiming specific ads at potential supporters based on where they live, the Web sites they visit and their voting records.

The technology that makes such customized advertising possible is called microtargeting, which is similar to the techniques nonpolitical advertisers use to serve up, for example, hotel ads online to people who had shopped for vacations recently. In the last few years, companies that collect data on how consumers behave both online and off and what charitable donations they make have combined that vast store of information with voter registration records. As a result, microtargeting allows campaigns to put specific messages in front of specific voters — something that has increased in sophistication with the large buckets of data available to political consultants.