"The Germans sell in English, but they buy in German." Danish proverb
Every customer expects the product to be presented in his own language. Being able to speak the language of the target group have a big influence on successful marketing.
Although nearly all Germans can make themselves understood in at least one foreign language (most of them in 2-3), they are averse to deal with important matters in English.
The knowledge of foreign languages is valued highly in Germany. You can´t get a job at a German company without very good German language skills
The advantage of (at least) bilingual employees to an export-oriented firm is obvious. Any company seeing a target market in Europe will be working to improve the language ability of its employees.
German speakers are the biggest group of potential business partners in the European Union, forming around one third of the population.
Also, the German language often plays a more important role than English in the developing markets in Central and Eastern Europe: German is an important language in many parts of Poland, Hungary, Romania, Russia, the Ukraine, the Baltic states and the Czech Republic.