One of the first things you learn as a copywriter (or a radio newscaster, in my case) is: Make it personal. Don't talk to thousands of people. Don't talk to some ephemeral "audience." Speak directly to one person.
Last week, MoveOn came out with a classic example of using technology to personalize a message. In this case -- Jan, get out there and vote! Take a look.
P.S. Thanks to Amber and Leslie for the link!