I don't know how to put this, but you have history backwards. The US government explicitly banned commerce on the early internet (i.e. the '70s and '80s). In 1980, the first social media network was created: Usenet (see my essay for more details on the history of Usenet). Meaningful commerce didn't occur on the internet until the 90's when the general public got access to the internet.

In other words, because of state intervention, social media came before commerce on the internet.