It is the latest move by Amazon to compete with grocery delivery services offered by Walmart+ WMT.N and Instacart. Previously, Prime subscribers' grocery orders were fulfilled through Amazon Fresh or Whole Foods. Now the additional service will complete orders through its same-day delivery logistics locations. Same-day delivery is free for Prime members, who pay $14.99 monthly or $149 annually, for orders over $25. Walmart's membership service, Walmart+, costs $98 a year and offers same-day delivery in under three hours—with some orders arriving in as little as 30 minutes.