Walmart is doing something similar and more to compete with the likes of Target and Amazon. Free 2-day shipping will be offered on many more items, including those sold by 3rd party sellers, and is available to all without a membership fee.
They’re also making it easier to return with printable return labels to ship items back to the sellers and, starting mid-November, in-store returns for select marketplace purchases.
ETA: it is now confirmed that Walmart will still require a $35 minimum for free shipping, so Target is the better deal, especially when you factor in Target’s 2-hour delivery and curbside pickup.