If an eligible item is ordered between 10 a.m. and 1 p.m., Amazon will have it delivered on the same day.
So far the service doesn't include Chicago, just New York, Philadelphia, Boston, Washington, Baltimore, Las Vegas and Seattle.
There is a cost for the added convenience. For Amazon prime members, it will cost an extra $6 an item. And for non-prime members, same day delivery will cost $15.