This document discusses multi-screening, which is using another mobile internet device like a smartphone or tablet at the same time as television viewing. It notes that around 75% of TV viewers now multi-screen, and looks at who is multi-screening, what activities they are engaging in on secondary devices, and why they are multi-screening. Both opportunities and threats of multi-screening for brands and advertisers are considered. Examples are provided of how some brands have successfully used multi-screening strategies, such as Volkswagen's use of targeted tweets around a Mad Men episode that increased engagement. The document concludes that multi-screening is now normal behavior for many viewers, especially millennials, and that successful strategies will respond to viewers'