To promote downloads of their mobile app, we attached the door of a Metro newspaper box to the front of a flat poster. When users open the door, they find a QR code allowing them to instantly download the paper on their phone.

Inside copy: Available anywhere. Download the Metro app today.

To promote downloads of the paper's mobile app, we placed mini Metro Newspaper boxes on busy city streets across the country. QR codes allowed users to instantly download the paper on their phone.

Inside copy: Download the Metro apptoday.

 To promote downloads of the Metro News app, we filled transit cars with blank ads, leaving passengers nothing to read but a call to action.

Copy: Looking for something to read? Download the Metro app today.