"where you were billed per minute by the ISP, the platform, and maybe the thing hosted by the platform as well."
And don't forget the phone companies. The idea of unlimited all-you-can-eat on a POTS line wasn't implemented everywhere, and it only made sense when you were on for thousands of minutes a month. On top of that not every town had a local portal to Source, Telenet, Compu-Serve, etc so it was a crazy-expensive toll call to get connected in the first place.