Vergangenheit:

• Wir/Unternehmen/Anbieter: Was wir in der Vergangenheit für jemanden getan haben.

Zukunft:

• Du/Kunde/Klient: Was du in der Zukunft bekommst.

When you speak with a customer, don’t speak about your past with others, tell him what he gets from you in the future.
In general, always speak about the «AFTERs», e.g. what is the state after the action, what will be the benefit after the projects etc. 

Source: Andy Bounds, «AFTER»