 In some cases, posts containing popular content or fast-breaking news have been rapidly shared and reshared by a huge number of users.Many social media sites provide specific functionality to help users reshare content, such as Twitter's retweet button, Pinterest's pin function, Facebook's share option or Tumblr's reblog function.Businesses have a particular interest in viral marketing tactics because a viral campaign can achieve widespread advertising coverage (particularly if the viral reposting itself makes the news) for a fraction of the cost of a traditional marketing campaign, which typically uses printed materials, like newspapers, magazines, mailings, and billboards, and television and radio commercials.