["Psychology &Marketing, EarlyView. ", "\nABSTRACT\nSustainability information is difficult for consumers to evaluate because environmental performance represents a credence attribute. Although numerical sustainability claims have been shown to improve consumers' perceptions of sustainability communication, little is known about whether they influence product choice under realistic marketplace trade‐offs or through which decision processes these effects emerge. Drawing on signaling theory, this research examines whether numerical sustainability claims function as stronger marketplace signals and investigates how visual attention is associated with their influence on consumer choice. Two complementary studies were conducted: a choice‐based conjoint experiment (N = 512) examining product choice and willingness to pay, and an eye‐tracking experiment (N = 45) investigating visual attention during product evaluation. Results indicate that numerical sustainability claims were associated with higher consumer preference and willingness to pay than equivalent non‐numerical claims. Eye‐tracking results showed that although numerical claims attracted greater visual attention, attention to the claims alone did not explain product choice. Instead, numerical claims were associated with broader visual attention during product evaluation. The findings suggest that numerical sustainability claims help translate sustainability communication into consumer choice under competitive marketplace settings.\n"]