Grocery delivery sure is competitive
                                
                                
                                    (Newser) -
                                    Look out, Amazon: Trying to keep pace with the online leader, Walmart is expanding its same-day online grocery delivery service to more than 40% of US households, or 100 metro areas, by year-end, reports the  AP . Tom Ward, VP of Walmart's digital operations, says the retail giant is powering...