If Amazon's growth rate decelerates by 1% each year for 10 years, they'd end up with ~$1.7 trillion in revenue, more than 3x walmart. That's more in line with what Amazon shareholders are expecting with the current valuation (i'm not one of them)
https://www.cnbc.com/2017/04/12/nearly-every-american-spent-...
At some point you will start to asymptote out. 1.7 Trillion is more than walmart+Target+3 of 4 big box retailers.
That seems very hard to believe. Trying to find more info on where those numbers came from, appears the NPD Group looked at 4 million receipts?
How do the segments that would avoid walmart not make up more than 5% of the US population? Those who are morally/politically against walmart, the very wealthy (likely have someone go for them, or don't shop at walmart), physically incapable, or not physically near (e.g. young people in cities with no car)