KFC, the fast food chain, learnt a thing or two about the power of Twitter, the messaging site that allows members to post 140-character updates for all to see, when it launched grilled chicken earlier this year.
Something of a departure for the fried-chicken specialist, the company's move into grilled chicken was unveiled by Oprah Winfrey on her show, with details of a voucher on her website for a free meal.
Once the link to the voucher hit Twitter, it was quickly forwarded to millions of users.
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