This chapter provides a detailed analysis of consumer choice in the case of differentiated goods under imperfect information. When information about product characteristics is imperfect, the collection of costly information leads to greater certainty about product characteristics, so that information is absorbed through Bayesian Learning to an optimal extent. The sequential collection of information thus leads to an optimal but incomplete absorption of information. Therefore, qualitatively different consumption decisions arise under the conditions of complete information and optimally collected information. This difference underlines the importance of information for rational decisions. Furthermore, it is shown that heuristic rules can be a subjectively rational and cost-effective alternative to expensive active information gathering. Although the chapter initially considers a simple consumption decision problem, it is shown that the human information problem is also relevant for more complex decisions. The insights gained from this analysis of consumer decision-making under incomplete information thus provide the basis for understanding how belief systems and ideologies can function as heuristic mechanisms for overcoming the human information problem in more complex contexts (politics, society).