[eridius]

"products made by one brand" isn't a category of products. If they're the only brand that makes products for a particular category, then they're a monopoly, but you cannot simply define a category as "stuff made by that company", because by that logic, every company is a monopoly on stuff made by them.

[dragonwriter]

Actually, a makers own products are a distinct market for antitrust purposes if people empirically don't substitute out of it, as shown by the producer having market (pricing) power.

I wouldn't be surprised if that's true for Apple for some of its offerings.

[eridius]

It's not. The only product you could even try to make the argument for is the iPhone, but the generally-accepted categorization here is that iPhone and Android phones (and Windows phones) are part of the same category, which makes sense because people absolutely do switch between them.

[eridius]

Actually I have a better argument against this than my other.

No, "products from brand A" is never a category. However, a company may create a brand new market with a product, and they may be the only company with a product in that market for a while. But that still doesn't mean the category is "products by that company", it just means it's whatever new category was created from the product.

For example, the iPhone arguably created a new category of smartphones. But competitors quickly introduced their own products in this same category (e.g. Android).