Try this hack to send postcards for free!

Have you heard of the legend that if you write “STS” instead of putting a stamp on a postcard, you can send it to anywhere in the world for free?

“STS” is supposed to be an abbreviation for “Student to Student”, some people argue that it actually stands for “Soldier to Soldier”. Legend has that after WWI/ WWII, to make it easier for poor students around the world to communicate, this postage…