Postcardware

Postcardware, also called just cardware, is software similar to shareware, distributed by the author on the condition that users send the author a postcard. The concept was first used by Aaron Giles, author of JPEGView. Emailware uses the same approach with requiring to send the author an Email. Lunchboxware is pretty much the same, except that you are required to show up at the software designer's place of work with a Boxed Lunch.