Someone asked in the Math.StackExchange chatroom what a "more refined word for circlejerk" might be. UrbanDictionary defines this (in our desired usage) as:
[...] pompous, self-congratulatory discussion where little to no progress is made.
A group discussion or activity between like-minded individuals that validates mutual biases or goals in a non-confrontational environment.
Sometimes used to describe an internet forum thread where forum members all give each other kudos (Or rep where a rep system is present) for some non-event that has occurred.
I guess it's related to "intellectual masturbation" or "echo chamber" but these don't quite fit the bill.