Zappos employees are actively encouraged to spend hours on the phone with customers, discussing anything from shoe size to family troubles (the record time for one call is just under six hours).

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Manti Te'o previously told reporters he and his girlfriend would spend hours speaking on the phone.

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Previous Interphone research on cell phone users' ability to recall how many hours they spend on the phone has found that heavy users generally underestimate that time, and light users overestimate it, Morgan said.

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