In its most recent filing, Buffett conglomerate Berkshire Hathaway (NYSE: BRK.A) (NYSE: BRK.B) reported no consequential new stock picks last quarter among Berkshire's top 25 stocks. Given that grocery in general is a low-margin business, digital ads can really move the needle for Kroger even at relatively small revenue numbers, and the company reported "record growth" in these alternative profit streams last quarter. And since Kroger also has a significant amount of fixed costs that won't necessarily go up with inflation, those gross margin dollars should fall straight to the bottom line.