Barack Obama’s campaign put its Facebook page to a new use just four days before the Iowa caucuses. Fans, or supporters, of Barack Obama received a message asking to remind their friends in Iowa to caucus.

The message, titled “3 Days to Go,” directs supporters to a page with all of their friends who have some connection to Iowa. You can check off the friends you want to invite to the caucus, and the app sends a caucus reminder to your friends.

Meanwhile, Jose Antonio Vargas reports in the Washington Post that Obama’s Iowa staff engage people in a variety of contexts, new and old, including Facebook messages:

In Sen. Barack Obama’s Iowa headquarters, young staff members sit at computers, analyzing online voter data and targeting potential backers. They zip one e-mail to an undecided voter and zap a different message to a firm supporter.

Depending on the voter, they follow with Facebook reminders, telephone calls, text messages and, most important, house visits.

It’s getting down to the wire. If Obama’s new voter contact strategies work, there could be an unsuspecting wave of caucus-goers completely missed by traditional tactics and polling surveys. For reference, here’s how Jerome Armstrong predicts the caucuses will go based on turnaround alone:

Turnout numbers        Favors

< 150,000                Edwards

150-170,000              Clinton 

> 170,000                Obama