It is very nice to give a feedback and I appreciate doing it but it is already the second message I get to do a feedback and I still haven't got what a have ordered.. My stuff is still on its way... I think you should only send this message when people get what they have ordered.
Strengths
Fast answers, very good service on the phone to explain how GLS works. Order arrived correctly with poster and magazines with it. No bad suprises.
Improvements or suggestions
Ask people to give a feedback only when you know they get their order.
Tell on your website the order to switzerland take at least 7 days. More something like 7 to 10 days.