Daily Impressions also known as daily effective circulation (DEC) is the average number of passers-by or persons (18+ years) in cars or other vehicles, that could potentially be exposed to an advertising display or billboard for either 12 hours (unilluminated – 6:00am to 6:00pm) or 18 hours (illuminated – 6:00am to 12:00 midnight) on an average day. For additional insight see Daily Effective Circulation
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