Mmm, not quite. Cluster analysis groups together cases based on similarity on the chosen variables. The classic example of cluster analysis come from Sir Ronald Fisher, who used cluster analysis to group irises (the flower) based on petal length and width and sepal length and width. So if you used this data, the cluster analysis would group the irises together two at a time based on which were most similar in terms of petal length and width and sepal length and width.
Clustering is used all the time in marketing to segment a particular consumer market. You can cluster consumers together based on purchasing, attitudes, brand perceptions, etc. This can help a marketer get an idea of what types of consumers are in his market and what they care about or what they tend to buy. It takes the full, heterogeneous market (population of consumers of that category) and breaks it into clusters of consumers who are more similar to each other than to those in other clusters. Hope this helps!