With a recent article and poll from Swiss Info, English might not be spoken as much as previously thought. They claim English might not be the official business language, but the most major flaw was which companies they polled. That answer can make a huge difference!
I've got a bit to say about this personally. For one thing, there are a lot of foreign businesses in Switzerland, so using English as a common ground language is most suitable. The main reason why English is used as the 1st business language, is because when people try to speak another language such as German, they can't understand them and would rather revert to English a language both mutually understand.
As well, most French speakers can speak English better than German because the learning curve for English is just plain easier. As well, many German speakers speak English above French. These are all from my own observations. Maybe it is not the norm, but still how I see English as the official business language.