[richardwhiuk]

Walmart has a monopoly on being the only people who can sell products in a Walmart store.

[adamc]

This seems disingenuous. Once you buy an iPhone, you need to buy apps from Apple's store. There is no similar force restricting you to Walmart.

This would be more akin to buying a Ford and then discovering you could only buy parts, motor oil, etc. by visiting your Ford dealer.

[gowld]

Switching from Walmart to Target and back and forth all day long is much easier than switching between phones.

A phone is a natural monopoly.