Lloyd, senior director of global marketing at McDonald's Corp., said the company has run a number of campaigns aimed at kids this year. The effort that won the company the most kudos was "The Lost Ring," an alternate reality effort focused on social media before and during the Beijing Summer Olympics.

The campaign--for lack of a better term for it--involved McDonald's creating a virtual-reality template and then letting participants get involved to determine how it would evolve. The effort included things like clues--written in the experimental early-twentieth-century language Esperanto--hidden in various buildings and monuments around the world.

Lloyd said the six-month campaign eventually brought teams of competitive "athletes" to Beijing to compete in a race through a labyrinth. Throughout, the McDonald's brand was all but absent--an approach that Lloyd says is emblematic of where the company is going vis à vis digital marketing to capture the 80 million or so millennials.

"They are community-oriented, optimistic, civic-minded and have $200 billion in spending power annually," she said. "They are digital 'natives'--part of a global youth culture." She adds that while they have high expectations for brands, "they are a very skeptical audience. They are over-inundated with content. So it is really important that they be entertained and inspired, not just marketed to."

She adds that they are peer-oriented and seek real-time feedback and instant gratification. "They are also very comfortable broadcasting opinions to peers."

McDonald's created a number of global Web sites in seven languages. "Rather than simply taking a site created in English and translating it, we created an experience in which characters who spoke these languages were therefore able to tell the story of 'The Lost Ring' in an authentic way."

Julie Channing, director of interactive marketing at McDonald's digital agency, New York-based AKQA, said "The Lost Ring" garnered over 2.6 million participants worldwide--across 100 countries, with over 9,000 mentions on Google, over 1,500 images on Flickr and close to 300 videos on YouTube.

She said marketing was sub-rosa, with viral outreach to some 50 influential bloggers. "Then we partnered with OMD to do a global-launch campaign, with local-market activation."

Said Lloyd: "The typical teen has 80 phone numbers and over 100 friend connections. Mobile media will be a 'game changer' going forward; we see mobile as a lifestyle trend driving tremendous growth. Our 24-hour business is great confirmation of the mobile lifestyle. And it's a global trend: anytime, anywhere."