Package size, shape, and elongation affects shopper judgment and decisions, but not always in easily uncovered ways. Shoppers appear to use these things as simplifying visual heuristics to make volume judgments. Generally, they perceive more elongated packages to be larger, even when they frequently purchase these packages and can experience true volume. This means that disconfirmation of package size after consumption may not lead shoppers to revise their volume judgments in the long term.