And the article goes on claiming that e-commerce and marketplaces, hardware, and ads are those few ways.
This can't be true considering how much money Netflix (subscription), AWS (metered pay), mobile games (IAP) are making.
It could as easily have started with "Marissa Mayer great!", and done the same (but with a different set of 'facts' and anecdotes).
The three ways of making money -- transaction fee, selling hardware, and selling ads -- exclude just paying for an internet service (where I would call subscription, metered, and IAP different ways for paying for a service).
You could call that a subset of e-commerce except that he defines e-commerce companies as those that "that profit from transactions occurring on their platforms," and uses Amazon, ebay and Uber as examples.
Also, they were presumably only talking about consumer web services. AWS doesn't fall into that category.