Unlike Fresh Direct, these services offer a lot more than cereal and milk. Google Express and Instacart employ shoppers that physically shop the aisles of participating stores. Amazon Prime Now makes overnight delivery look like the Dark Ages with their fully stocked warehouses that's stocked with everything from food to Play-Doh to technology and workout gear. The options are truly mind- boggling.
We've been ordering and consuming through all three companies for the past several months. These services all offer same day delivery within Manhattan but their specialties and fees slightly differ. Above is a handy cheat sheet that breaks down the major differences and our opinions. You can click on the image to enlarge the text.