Incorporating external data into data warehouses is a rather unexplored area and deserves more attention, especially if considering the resources organizations spend on acquiring data from specialized data suppliers. Therefore, this paper gives the results of an interview study partly aimed at evaluating, from a general perspective, the outline of such a process and related problems. The results show that trust and cost issues are utmost important characteristics to consider when acquiring external data. In addition, the results also show that the organizations incorporating external data need some type of hands-on support, for being able to fully exploit the potential thereof. Finally, the results also gave the outline of the external data incorporation process.