Earlier quoted context omitted.
> Given that iPhones account for just 35% of US mobile phones [1] and only around 15% of phone shipments worldwide [2], this is in no way monopolistic. What is monopolistic to you? Does it need to be over 50%? I don't think economists define it that way, they only argue that one company has excessive influence in a market, which means more power than the other companies in that market. That does seem to be true of Ap…
That reporter is right though: Walmart isn’t a monopoly. Not generally. It can have a local monopoly of course (and often does in many more rural areas) but that’s not the same. I think I’ve been to a Walmart once in the last 10 years. I’m not even trying to avoid them: there’s no reason or need for me to go there and I have plenty of other (just as cheap) options. That’s not a monopoly. They’re a massive business an…
That said, your experience and you having other purchasing options isn't the only criteria, as @s3r3nity pointed out. Being on Hacker News probably means you're not in the lower 50% of the US population socioeconomically.
Being a massive business is precisely one way Walmart might be considered a monopoly. They're not a dominant national brand, they are the single largest global brand on the planet by revenue. The fact that if Walmart closed tomorrow, it would have a significant negative impact on the US economy is alone enough to warrant asking the question. When a company is "too big to fail" that automatically puts it in the potential monopoly category.
Also, there have been anti-trust cases against Walmart, some of which Walmart has settled. So it's really not super clear cut that Walmart isn't a monopoly.