It may seem counterintuitive, but overtly promotional content, such as sweepstakes, special offers and contests, should be only 10% of what your company's fans and followers see, says Mr. Chaney.

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But they undervalued the use of contests, sweepstakes and promotions to stir engagement.

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They buy names of people who have entered contests like sweepstakes, and troll for the isolated and lonely ones who will talk to someone on the phone.

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Mathis, through his attorney, has also insisted that Mathis did nothing wrong and the games were legal sweepstakes, much like contests sponsored by fast-food restaurants or retailers.

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