Candidates in the race to win the nominations for next year's US presidential election are being offered a service that will allow them to target e-mail advertisements directly at registered Democrats and Republicans.

Aristotle Publishing, which specialises in providing Internet services to political organisations, is working

with leading Internet service providers to match the names and addresses of users with the state lists of registered Democrats and Republicans.

The result will be a database that allows messages to be sent only to people with one party affiliation or the other.

Being able to target these people is especially useful as they are often motivated by the more extreme political messages, which if broadcast generally could turn middle-of-the-road voters against a candidate.