A two-step model with sample selection is applied to panel data of U.S. households to estimate at-home demand for fluid milk and cheese, incorporating advertising expenditures. The model consistently accounts for sample-selection bias, unobserved household heterogeneity, and temporal correlation. Generic advertising programs for fluid milk and cheese were effective at increasing conditional purchase quantities, with very little effect on the probability of purchase. In contrast to aggregate studies, the long-run generic advertising elasticities for cheese were larger than for those of fluid milk. Advertising response varied considerably across sub-product classes, while branded advertising expenditures were largely insignificant.