At a time when many brands are stuck in experimentation mode in social media, Pepsi is placing a staggeringly large bet on it. Pepsi was absent from the Super Bowl for the first time in 23 years, redirecting money to an ambitious social marketing-centered program called Refresh Everything that will direct $20 million to charities. According to Pepsi execs, the program is appealing because it rested on four big trends: crowdsourcing, doing good, sharing and transparency.

Refresh Everything is the culmination of years of social-media work done by Pepsi, the perpetual No. 2 behind Coca-Cola in the soft drink market. Pepsi’s still a big spender in traditional media — it spent $89 million in U.S. advertising on the brand in 2009 — but Coke outguns it by a 33 percent margin. Social media, offering a more level playing field, is where Pepsi is making its stand with one of the largest commitments to the space yet seen.Yet Pepsi execs are at pains to point out that Refresh Everything is not a social-media campaign per se. Rather, it uses social media as glue to hold together a wider push that includes traditional elements like TV spots, says Bonin Bough, PepsiCo’s director of social media. It even includes a dash of Pepsi’s usual celebrity tie-ins with the inclusion of Hollywood stars Demi Moore and Kevin Bacon, and New Orleans Saints quarterback and Super Bowl hero Drew Brees.

When it comes to measurement, Bough’s team has developed a scorecard with different elements that tie back to brand health and relevance. It will gauge, via standard research methods, whether people’s perception of Pepsi changed.

Pepsi is using social monitoring tools to track share of voice and mentions in social media and traditional media, as well as harder engagement metrics like visits to the Refresh site, time spent, submissions and votes. It will try to gauge whether the program makes an impact in communities. The overall aim is to follow in the footsteps of decades of Pepsi marketing. “Our goal is to skate to the center of culture,” says Bough. “Right now, digital is culture.”

Pepsi has the advantage of experience to draw upon. It has launched several social-focused efforts for brands. Tropicana created the Trop50 community site with Blogher last year to reach women bloggers. Mountain Dew launched Dewmocracy, which designated to consumers its marketing plans. “We’ve already gone through the experimental phase,” notes Bough.

While Refresh Everything is a risk, Pepsi has drawn the notice of Coke. Soon after Pepsi announced Refresh Everything, Coke began a Facebook campaign and now donates $1 to the Boys and Girls Clubs of America for each visitor and every time a virtual gift is sent.