When it comes to advertising during the Big Game, second-screen media consumption continues to be a Big Game changer. Years ago, marketers were content just having their ads reach a captive audience of 100+ million viewers.

But as watching and critiquing the ads became as big a part of the viewing experience as the game itself — and the cost of air time during the broadcast skyrocketed — brands have looked for ways to generate more return on their investment.

That meant drumming up pre- and post-game attention by generating earned media impressions to complement their ad buy. And things have continued to evolve over the last several years as marketers attempt to engage fans who’ll be watching the game while simultaneously interacting with their tablets, smartphones and laptops.

We’ve had an opportunity to help Coca-Cola promote its Big Game advertising since 2008 — focusing on a blend of traditional and social media outreach to build buzz. This year’s effort stands out as the most unique campaign to date, as Coke gives fans the power to influence the ad’s storyline in real time.

We unveiled the campaign to media on Tuesday via a well-attended webcast and we’re in the midst of a large-scale blogger/influencer relations push that will continue until game time and beyond. Response to our launch efforts has been outstanding, with a ton of social media chatter and positive reviews/stories from traditional media outlets including Mashable, USA Today, the Associated Press, New York Times and Fast Company.

Here’s a little summary of the campaign and a bit more information about how you can get involved.

A 60-second spot, entitled “Mirage” will air during the game’s first half. It features three unusual factions — a band of Cowboys, a gang of “Badlanders” and a pack of Vegas-style Showgirls — as they chase after an elusive bottle of Coca-Cola they spot in the middle of a blazing hot desert.

The groups set off on horseback, dune buggies and a glittery bus attempting to capture the object of their affection. Members from each faction are caught up in playful skirmishes and melees as they speed across the sand, until they finally arrive at their destination… which turns out not to be an actual Coke, but a billboard promising refreshment a mere 50 miles ahead.

That’s where fans come in, as the factions take off in the direction of the sign and the spot directs people to a microsite to follow the action and help decide who’ll get the Coke by voting for their favorite group or sabotaging others. It’s all lighthearted fun and there will be additional content and updates available on the site and across all social media platforms. Ultimately, a payoff spot with three alternate endings will be cued up and ready to air immediately following the game, after the final votes are tabulated.

You can visit CokeChase.com for a sneak peek at “Mirage,” which was created by Wieden + Kennedy, as well as backstories and information about each faction. The first 50,000 My Coke Rewards members who participate will receive a free 20-oz Coke, so be sure to check it out and let us know who you voted for.