Google to allow candidates to target ads by House district

Political candidates will be able to target online ads to users within specific congressional districts under a new system unveiled by Google.

The feature is part of Google's AdWords product, which allows users to buy ads not only on Google, but on thousands of sites around the Web. Advertisers previously had been able to display ads only to users within particular zip codes, but the new feature will allow targeting to any of the 435 congressional districts. The feature will be especially helpful for candidates running in oddly shaped districts, which may sprawl across sections of numerous zip codes.