For me it started with online purchases of books when the web went commercial. Later still books, music and audio books (CD), movies (DVD, Blurays), electronics, computer consoles and games, physical games, PC hardware, and more often used goods via marketplace.

In Germany we also have many good alternatives. Online I use for example Thalia, Booklooker, Zweitausendeins, Technikdirekt, Roboter-Bausatz, Alternate, Rebuy, Medimops, Konsolekost, … And from Poland of course GOG, my favourite game store :)

This sounds interesting, thanks for sharing. Have now read through the page and FAQ. Is my understand correctly, that this app is only for paying in offline world, not for online purchases like e.g. PayPal?