After internal reporting, we want to deal with external communication in this chapter. Internal reports convey hard numbers, data, and facts, while messages to the outside often communicate more generally formulated content. Communication cannot be sharply distinguished into “internal” and “external” effects. Employees and partners are always also recipients of the messages and cannot (or should not) be excluded. What are the specific requirements for external communication in the context of sustainability? To what extent can advertising messages, which are naturally highly condensed, also transport complex topics? These and other questions are addressed in this chapter.