It's less than 12 hours until the Iowa caucuses and while Mitt Romney is ahead in the latest polls, Ron Paul is winning on the Web.

A new Facebook data analysis from the independent media analytics group Socialbakers shows that among the GOP candidates, Paul has the greatest viral reach, the most engaged fans and largest increase in Facebook engagement over the past month.

Socialbakers CEO Jan Rezab said Facebook has now become a vital aspect of presidential campaigning, helping candidates secure support and build trust with prospective voters.

"There was not a platform before where there could be mutual communication between the candidate and the fan and also among the fans," he said. "It makes people's voices amplified."

Paul's engagement rate, defined as the number of "likes" and comments on his posts divided by his total number of fans, increased 69 percent over the past month, trumping all other presidential contenders, including President Obama.

But while Facebook users are chatting up a storm about Paul, they are flocking to Rick Santorum. The Pennsylvania senator increased his fan base by 23 percent in December, outpacing the second-biggest gainer, Jon Huntsman, whose following grew 18 percent.

When it comes to person-to-person interactions such as comments and conversations, Michele Bachmann seems to be sparking the most debate. More users comment on, share and "like" her posts than any other candidate's.

And if there is any question whether polling numbers resonate with Facebook users, Mitt Romney's recent fan explosion online, which directly correlates with two polls showing he is on top in Iowa, seems to dispel any doubts.

The polls, one from CNN and the other from the Des Moines Register, came out last Thursday and Friday, respectively. In the span of those two days, the rate at which fans were flocking Romney jumped from about 1,200 per day to more than 7,000 per day, according to the Socialbackers analysis.

The polls had a similar effect on Santorum, who shot from sixth to third place over the past month. That big bump in the polls translated into a mega-boost online. Santorum's Facebook fan base grew 10 times faster than at any point during his campaign over the two days that the polls were released.

President Obama, who triumphed at social media campaigning in 2008, is dominating his GOP rivals this year when it comes to sheer numbers of followers. About 24 million people are Obama "fans" on Facebook and a full 50 percent of all election-related interactions on the site involved Obama in December.

"In four years, [Facebook] has developed to become less about fans and more about fan engagement," Rezab said. "By looking at the levels of engagement we can see how valid a person's support is."

But can that online support translate into votes on Election Day? A Pew research study suggests they might.

A 2010 Pew Internet study showed that Facebook users were 2.5 times more likely to have attended a political meeting or rally, 57 percent more likely to have tried to convince someone to vote for a specific candidate and 43 percent more likely to vote.

"Facebook is where the people are, where all of the people are," Rezeb said. "And candidates adapt to that by putting out smaller content pieces and content they wouldn't have done before."