All media - social or otherwise - could be behind a paywall. That is how it used to be except for hobby BBS systems. I think I said it already, but as a reminder, the advent of domination by advertisements came from the web being tiny and kind of hard to get into compared to other systems that back then depended on a CD that had the program on it. AOL mailed those things out by the millions over the years. You loaded the program and bang - “you’ve got mail!”
Getting onto the web required at first that you have 2 different programs that you had to carefully configure loaded onto your Mac (which is what I had) and you had to have an account with an early ISP (Internet Service Provider). The big companies like ATT and Verizon didn’t offer that. In Europe forget it at first. Telecom was still in the dark ages with their PTTs, until the mass use of mobile phones.
In 1995 I was flown by Apple to New York and Los Angeles to give a talk in their big day-long event called the Apple Multimedia Road Show. The NY event was in a huge hotel right at Times Square. This is 1995 and I was the only person there talking about the Internet. Everyone else on the agenda was talking about CD ROMS. Can you imagine?
I I get up there and my first slide says “The Web is Like Rock and Roll.” And I said to them the Internet and the web was going to crash like a tsunami, and soon. Most in the crowd seemed to look at me sort of like, “huh?”
Anyway the point is that those of us with a lot of content to offer on the web (like news - we had a ton of it) had almost no chance of luring even modest numbers of people into paying for our initial product, especially if it was such a hassle and expense just to set up to use the thing when those CD services worked with a plain old phone line.
So, ads…going that route brought us big numbers over time. Then it became the train you couldn’t get off of.
Now with paywalls they are trying. But we still route around them whenever we can, seems like.