People argue companies like Walmart don't want to pay their rival Amazon for cloud hosting, but the truth is if AWS is the best cloud provider, it makes business sense to go with them
Amazon is huge... but Walmart is truly massive... over double Amazon's size in just about every metric. They clearly have the resources to handle things on their own.
[1] https://poseidon01.ssrn.com/delivery.php?ID=0340721260780250...
[2] https://corporate.walmart.com/newsroom/company-facts#:~:text....
[3] https://corporate.walmart.com/askwalmart/in-which-countries-....
(6000 employees in 2018, per wikipedia)
Walmart doesn't have the same capabilities. Being larger doesn't mean they can do it.
The case of Amazon using internal market place data to guide their own product strategy has already been made over and over, so the precedent exists.