Ad Week: Agencies on Canal Street Are Waging a Post-it-Note War, and It's Awesome That was early last week. By the weekend, a full-blown Post-it note art war had erupted on Canal Street in New York City, with a number of agencies participating—including Havas Worldwide, Horizon Media, C...
Morning Update: Ad agency Post-it wars; Facebook adds video ads; Twitter to expand 140 characters