WSJ reports that Walmart is partnering with Burger King to offer new benefits for Walmart+ subscription members:
free Burger King whopper every 3 months with any purchase; this benefit begins in September
25% discount on all digital orders at Burger King; this benefit starts today (8/22/24)
Starting this week, Walmart+ members will get 25% off all digital orders at Burger King, and beginning in September, a free Whopper once every three months with a Burger King purchase. Amazon Prime earlier this year introduced free delivery of many restaurant meals through Grubhub.
Sounds like you could order a coke or something cheap and get a free Whopper.
This is apparently to compete with the Amazon Prime benefits at Grubhub.