You may have read a few months ago that the Well, an early Internet discussion forum, was put up for sale by Salon, which had owned the Well for some years. There was utter consternation on the Well itself over this, because the system has, well, bounced around a bit over the years.
The sale went through yesterday, to a small group of longtime Well members incorporated as The WELL Group, Inc., led by the amazing Earl Crabb. They were able to hang on to the domain name, which had been a concern; some users only use the Well for email, and they provide a significant amount of income.
If you're interested in intelligent conversation with no advertising and no data mining (the Well's conferencing system is not crawled), the Well offers a web-only account for $10/month and a web or SSH account, with email, for $15/mo. The web-based interface is strictly no frills; the Pico interface is fast, flexible, and old-style.
Yeah, I know, everywhere else is free. However: no ads, the best privacy on the web, and a lot of good conversation. To sign up, SSH to well.com or browse to the Well.