Integration of internal data is often mentioned in literature as the most demanding task when building or maintaining a DW. There is no literature that outlines the approach for the integration of external data into a DW. The integration of external data has increased during the last years enabling corporations to understand the opportunities in the market and to be able to better plan for future success of the corporation. The aim of this work is to exploratory outline current approaches for acquiring and integrating external data into DW and to give a brief overview of the future trends for external data integration. This aim was researched using an interview study. The results show that how to integrate external data is depending on what the corporations purpose with the external data is. Additional results show that how to integrate external data also depends on how the data is acquired.