Considering Amazon was building physical warehouses, buying land, literally delivering to people, executing deployment of AWS which Netflix was famously using, all while being a publicly listed company with audited public financials I think Amazon’s style is easy to distinguish from the outside.
https://www.macrotrends.net/stocks/charts/AMZN/amazon/profit...
You also know from using Amazon that they were near flawlessly executing 2 day shipping across the US with prices competitive with Walmart and other successful retailers.
They also had a pricing advantage against incumbents due to not having to collect sales tax in all states until 2016.
It’s mostly the verifiably not losing money part though so you knew they weren’t overextending, and they were delivering what people wanted.