According to Huggies, studies suggest that once babies become mobile, they can cover anywhere up to seven kilometers, or about 4.3 miles, in a single day.

The Kimberly-Clark is brand using this surprising statistic as the basis for a funny online campaign titled the "World's First Baby Marathon," promoting its diapers as the choice for mobile babies.

The campaign, created by Ogilvy, follows four babies whose diapers have been fitted with tracking devices, as they complete a 21km assault course around their homes. The babies are given amusing names like "Thunder Pants" and "Danger Boy" and their progress is edited into webisodes with names like "Hitting the Wall," with narration that parodies real-life sports commentary. (You can watch all the episodes at the campaign website.)

It's certainly a cute idea, and also gets across the product message that Huggies produces "comfy gear for moving babies."