With the Red Balloon Challenge, the team recruited more than 5, 000 people, with some referral chains containing as many as 16 people.

ECONOMIST: Monitor

One of the first examples was the Red Balloon Challenge, staged in 2009 by DARPA, the research arm of the American Department of Defence.

ECONOMIST: Monitor

Compared with the Red Balloon Challenge this was much more difficult, says Dr Rahwan, who is now at the Masdar Institute in the United Arab Emirates.

ECONOMIST: Monitor

The difference, however, was that the Red Balloon Challenge was not a crisis, so participants had to find another way to motivate others to report sightings of the balloons.

ECONOMIST: Monitor

The balloon's red and white wreckage was found in the Pacific Ocean south of the capital, Lima, the state-run Andina news agency reported.

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Kai-Lan makes the shape of a heart with her hands, sending a bright-red heart into the air like a balloon.

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The interesting thing about the balloon event is that it not only boosted the Red Bull brand, but simultaneously created the beginnings of the Felix Baumgartner brand.

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As a rite of passage, the record-breaking Red Bull event built pent-up attention at least twice as we waited for the balloon to launch Baumgartner into space.

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Red Balloon's fees are paid by the local education authorities - primarily Cambridgeshire and Suffolk - which refer children to it.

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