Hi, a little more than a month ago we have launched our very own online-bookshop Bookzilla.de as a partner of Libri.de (a books distributor). The system runs on machines with Debian GNU/Linux.
We receive a commission of 5% on every article, which we donate 100% to the Free Software Foundation Europe <http://www.fsfeurope.org/>. So if you are planning to buy some books, CDs or DVDs, you may want to consider doing so at <http://www.bookzilla.de/>. Best regards, Stefan Richter and Thorsten Ehlers on behalf of the Bookzilla.de-team