Among name checked brands like General Mills, Levi and AT&T, Verizon (the owner of Engadget's parent company) is specifically cited for beginning a test that will put its ads on Amazon boxes delivered to FiOS-serviced ZIP codes. It's doing more advertising on the site even though, unlike Comcast, it doesn't actually sell service via Amazon (yet). We've seen Amazon advertising its own products on packaging and extensively in search results for a while now, but that seems to just be the beginning.
The logic is that while others like Google and Facebook also have extensive data on customers (that could be linked to purchasing history) when people are on Amazon, it has their data for targeting and they're already in the process of shopping for something. Of course, Amazon is still trying to sell me a new digital scale just because I bought one five years ago, so we'll see what that information is actually worth.