What's the Difference Between Amazon and Walmart?

A lot of people, I've messed with Walmart about 2016, 2017 when it first started. It was a disaster back then. Some people have great success on Amazon. They go to Walmart and it's a total failure. Other people are the exact opposite. They can't crack the top 15 on Amazon, but they're crushing it at Walmart. What do you think it is that's important to understand the differences between the two marketplaces and what works and what doesn't work? "I'm not selling on Walmart right now"