I was a bit late for Usenet, but I do remember using newsgroups. You needed a newsreader although I think email clients could access newsgroups as well in the later days. In the corporate world, there was something similar inside of Microsoft Outlook called Public Folders. It was massive in one of my workplaces - it had folders for buy/sell, wanted, lost&found, let/rent, debate forum, discussion groups on pop, indie, dance, jazz music, computer discussion, TV & radio and many more. A lot of people got into trouble though for posting during core time, and the debate forum (called the Soapbox) was the most monitored folder by far. A number of people got the sack for stuff that they wrote in there as it upset the management!