Joe Ruiz, director-merchandising strategies at Campbell, Camden, N.J., said when the company installed the systems in 2002 it saw an initial sales lift of 5% and a 3% sustainable lift. "It's driven by where we put the system and what the customer base is," said Ruiz. "We've seen lifts [as high as] 5-8% [but as low as] 1-3%."
When I first saw the gravity-feed system in a store, it appeared to me to take more space per SKU, but that just shows how little I know, it seems. McCormicks also has gravity-feed systems for spices, according to the article, although I must admit I don't recall ever seeing one.