Before it became commercial, the web was social.
By the late 1990s it was definitely more commercial than social.
Then, with the fast growth of dedicated social media channels like Facebook and Twitter, it became seriously social again.
The arrival of the smartphone in 2007 made the web even more social. Smartphones are, by definition, social devices. And many of the most popular apps for these devices are hard-core social.
And then…
And then social media became a commercial broadcast channel.
OK, that’s the short version.