If confronted with a yes-no question too early, Germans react instinctively with a no. They reject any form of pressure to commit to something.
Even after having provided in-depth information and advice to a potential customer the German salesperson will be careful not to ask the closing question "Do you want to buy?".
Instead they will state their continued availability to answer any and all additional questions. Germans are allergic to any form of direct selling. Hard selling has a particularly bad reputation.
German consumers avoid the pressure applied by direct sales by seeking out expertise in their network of personal and professional contacts, including using online social networks. Germans want to take their time before making decisions. An intelligent sales approach respectfully gives them that time.