Firms today offer more diverse products to induce consumption. Does the variety of choices always enhance consumers’ choices of more varieties? Intuitively, the larger the choice set size, the more varieties consumers will choose. However, the present research argued and found that there was an inverted-U relationship between choice set size and variety seeking. Specially, as choice set size increased, consumers’ variety seeking first increased and then decreased. When choice set was too large, consumers were more likely to use heuristic processing of information, which led to the decrease of variety seeking. Studies 1A and 1B first showed the inverted-U relationship between choice set size and variety seeking with different products. Both experiments used a single factor between-subject design with three choice set size groups: a small choice set (6 flavors), a moderate choice set (12 flavors), and a large choice set (30 flavors) of yogurt (Study 1A) or ice cream (Study 1B). Subjects were randomly assigned to one of the three choice set size groups. Results showed that, for both experiments, consumers’ variety seeking first increased as choice set size increased from small to moderate, but consumers’ variety seeking then decreased when choice set size increased from moderate to large, supporting the inverted-U relationship between choice set size and variety-seeking (H1). Studies 2A and 2B aimed to test the proposed underlying mechanism, namely the heuristic information processing, by examining the moderation effect of individuals’ need for cognition (NFC). Study 2A used a 3 choice set size (6 vs. 12 vs. 30) × 2 NFC (low vs. high) between-subject design and showed that NFC moderated the inverted-U relationship. Specifically, the inverted-U relationship was only observed for low-NFC participants, but not for high-NFC participants (H2). Furthermore, in the large choice set condition (30 flavors), participants with low NFC showed more variety seeking than those with high NFC (H3). These results suggested that low-NFC individuals applied heuristic information processing to pursue more choice variety, while high-NFC individuals applied analytic information processing to pursue the most desirable choice. Study 2B used a 2 choice set size (6 vs. 30) × 2 NFC (low vs. high) between-subject design and demonstrated that NFC moderated the information processing style, which led to the inverted-U relationship between choice set size and variety seeking. Specifically, low-NFC individuals showed more heuristic information processing in the large choice set condition (30 flavors) than in the small choice set condition (6 flavors), while high-NFC individuals showed more analytic information processing in the large choice set condition (30 flavors) than in the small choice set condition (6 flavors). Study 3 was designed to further test the underlying mechanism by manipulating cognitive difficulty. The results showed that the heuristic information processing caused by difficult-to-read font could lower variety seeking even in the moderate choice set. Together, these results provide consistent evidence for the proposed heuristic information processing underlying mechanism. In summary, the current research has shown that, contrary to the common wisdom that more choices lead to more variety seeking, there is an inverted U-relationship between choice set size and variety seeking. These findings have important implications for firms. To induce more variety seeking and more consumption, firms may want to offer moderate rather than large assortments of products.