In 2011 writer and artist Anne O. Kubitsky printed out 500 invitation cards asking people to share what they’re grateful for in a postcard (and mail it back to her). She left these cards in various places, everywhere from post offices to parks to college cafeterias to libraries.
Within three weeks she received handmade postcards from all over the world – from Oregon to Alaska to Australia to Germany. Today, she’s received thousands of responses in many different forms: letters, emails and even phone calls.
People also have submitted postcards made from leather and clay. One person submitted a 12-year Alcoholics Anonymous sobriety medallion.