I fight with the MySQL forums, and wish for an NNTP/IMAP interface. I sort out the "mailboxes" on various social network sites, and groan, wish that I could just point my IMAP client at them.
Public discusion forums, such as GoogleGroups, YahooGroups, eBay forums, BoingBoing, LJ journals and communities, Slashdot, MySQL forums, plus all the precanned turnkey webforum software, and all the political rant cesspools, from LGF to DK, all of you: NNTP or IMAP. Now.
If your answer is "but then, people won't see my ads", you're a fool. Anyone clueful enough to run a reader client is already running Adblock, and so already isn't looking at your ads. And if you really think your ads are contentful, roll them into the article stream and into the article bodies.
That it's not been done is idiotic. That is not being done right now, remains idiotic.
Yes, I know I'm calling a lot of smart people idiots. It's still true.