It's possible to use a computer network for commercial transactions. For example, use the network to transfer data to browse selections of products and services, make payments and complete purchases.
It's also possible to use a computer network for advertising. For example, putting ads one every page of every website so when a www user is reading some noncommercial page, ads are everywhere. Or when a www user is communicating about noncommercial topics over someone else's website,^1 ads are everywhere.
1. A dumb idea because of "tech" company surveillance and ads
IMHO, the two are not mutually inclusive. Perhaps there are only so many widgets that can be sold over the web. But with ads, there is no limit. The ads are not there to provide "free" services despite the messaging from Silicon Valley. The ads are there so that so-called "tech" companies can make money. They do not even have any widgets to sell. They have nothing that web users will pay for. Thus, surveillance and ads.
A common retort every time someone mentions that the original web had no ads usually goes something like "The early web sucked" or "I don't wan't to go back to the early web". But that is not the point of mentioning the original web. With today's hardware, there is no going back. The internet is incredibly fast now. It does not have to suck anymore.
The point of mentioning the early web without all the ads is that bogus claims by entities like Mozilla that "the web needs ads to survive" or by Google that they are "making the web faster" while still delivering same/more ads are pure nonsense. The web does not need ads. Ads are what makes the web slow. Google deliberately adds delay to webpages when they "load" so ad auctions can take place.
At the same time, it is common to HN commenters reminiscing about the early web and complaining about the current web.