The big picture: If Walmart was ever going to launch a subscription service to challenge Amazon Prime, now is the perfect time to do so. Some of the perks we expected to see bundled in the membership weren't mentioned in today's press release but it's still early. Walmart has plenty of time to bolster the service with additional perks to make a serious run at Amazon.

Walmart on Tuesday officially introduced its long-rumored membership program. Walmart+ aims to roll the best in-store and online benefits into a single program to save users both time and money.

Initially, Walmart+ subscribers will have access to unlimited free delivery on more than 160,000 items. Up to this point, this perk was known as Delivery Unlimited. Current subscribers will automatically be converted to Walmart+ members, we're told.

Walmart+ members will also be able to use the Scan & Go feature in the Walmart app to scan their items as they shop and pay using Walmart Pay, thus avoiding long checkout lines.

Subscribers can also use their membership to save up to five cents per gallon at the nearly 2,000 Walmart, Murphy Express and Murphy USA fuel stations across the country. Walmart said Sam's Club fuel stations will soon be added to the list of participating retailers.

Walmart+ will be priced at $12.95 per month or $98 a year when paid up front, a savings of $57.40 over the month-to-month rate, when it launches on September 15. Interested parties will be able to sign up for a 15-day free trial to see if it is a good fit before shelling out any money on a membership.

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