Interesting. Initially, I was thinking "But Amazon could only ever eat into a small-ish percentage of Google's total revenue, because Lowe's and restaurants and such will still want to advertise on Google so long as anyone is using it for search." However, I think there's a clear avenue around that: allow Amazon to index and ship Lowes' products. This would allow stores to stop supporting their massively expensive e-commerce operations (or significantly reduce them), especially if Amazon allowed the store to have significant individual branding when you're viewing a product they list. They could even index movie tickets and restaurants, which would mean you could Amazon your "night out," reserving tickets and dinner online, in one place.