• Wendy's "Where's the Beef?" - Distributed tens of thousands of t-shirts with the classic phrase to those that liked their Facebook page, Wendy's currently sits at 2.3 million likes.
• Mr. Clean - P&G ran a campaign with a "mustache o' meter" in conjunction with Movember, a men's health fundraiser and awareness campaign.
• Coca-Cola "Hilltop" - Campaign gave customers the ability to give a coke to people on the other side of the world.
• "Got Milk?" - Leveraging the classic phrase to attack soy milk, the campaign allowed consumers to conduct experiments on the "science of imitation milk."
• The Coca-Cola Polar Bears - Before the Super Bowl, Coca-Cola used the bears to beat internal Facebook goals by 15x and featured an entire day of tweets only from the Polar Bears.

From the article:

Over the last few years, many brands have found new success by dusting off classic marketing campaigns and invigorating them with new life via digital extensions. The staying power of these classic campaigns was often rooted in iconic taglines, compelling imagery, or memorable mascots, and those qualities translate perfectly to new digital channels and tools like Twitter hashtags, Facebook profiles, and interactive gaming.

With the advent of these new digital channels, brands have been able to breath new life into their old-school marketing campaigns and introduce their brands...