Swiss German is spoken not in Germany but in Switzerland. It is the everyday language of the Swiss but it is not German. You will know with the differences it has with the sounds, pronunciations, and the grammar used. One thing you should know about this language though is that it is not a written language. When the Swiss people write they do so with high German, the kind of German language that is spoken by German-speaking countries in Europe.
So why should one learn Swiss German? There are many answers to that. Zurich and Geneva as the two global cities are actually found on the plateau landmass of this landlocked country. So if you are after big time business ventures which demand you to be in joint partnership with a Swiss businessman, you better speak his language. It helps when you know German since the Swiss people can speak perfect German as well, but it is different when you know of Swiss German if you are to speak to him as a friend, an ally, or a partner at that. Do not ever forget that if you have great opportunities for you in Switzerland, you have to take really good care of that opportunity as Switzerland is one of the richest countries of the world. Zurich and Geneva in fact have been ranked as second and third (respectively) highest quality of life in the world. It could be because the country has not been invaded during the two world wars.
Switzerland also tries to avoid as much as possible any agreement or union that would entail political, military, or direct economic moves, making it free from any responsibilities with other nations and instead focusing on their local affairs. That It however became a good venue for espionage on both warring sides during the world wars.
Thus, it is not surprising that there are many international organizations found in Switzerland. There is the Red Cross, WEF, World Trade Organization, and even the second largest office of UN.
The Swiss people speak in Swiss German, sort of made up language which foundation is the German language. But most Germans would find it funny since the language has a different set of pronunciation, grammar, and accent. The Swiss unlike those who want to learn the British and French accents are proud of their strange accent which is not German at all. What everyone should know is that the Swiss German language is a combination of the many dialects that are found in Switzerland. That's probably why they are proud of it.
Those are just some of the reasons why learning Swiss German is a must. The good thing about it is that you do not have to do it with a personal language trainer. You can just listen to a Pimsleur language learning audio program on your iPod and you're good to go.

