I recently blogged about motivating people online by getting them to work together for a prize or reward. This is neatly demonstrated here by Dingo – a dog food brand from Ohio, US. They ran a promotion which would only be released once their Facebook page had achieved 5,000 likes. This meant it was in fans’ interests to encourage their friends and contacts to ‘like’ the page too. Brian Solis reports they hit the 5,000 mark in just 3 days (Note: keep an eye on Facebook’s promotions guidelines when running competitions).