In the USA, younger millennials (18-24), spend an average of 91 hours a month in smartphone apps, about 18 hours more than people who are 35 to 44 and 33 hours more than 45 to 54 year-olds. Millennials spend an average of 30 hours a month in social apps. They are spending more hours on Instagram and Snapchat, which both only recently opened their services to advertisers, and in messaging apps like Facebook Messenger and WhatsApp, which do not yet have ads. Click here to read more about how apps are changing the game.