I like to read posts on "Main" from time to time, including ones that haven't been promoted. However, lately, these posts get drowned out by all the meetup announcements.
It seems like this could lead to a cycle where people comment less on recent non-promoted posts (because they fall off the Main non-promoted area quickly) which leads to less engagement, and less posts, etc.
Meetups are also very important, but here's the rub: I don't think a text-based announcement in the Main area is the best possible way to showcase meetups.
So here's an idea: how about creating either a calendar of upcoming meetups, or map with pins on it of all places having a meetup in the next three months?
This could be embedded on the front page of leswrong.com -- that'd let people find meetups easier (they can look either by timeframe or see if their region is represented), and would give more space to new non-promoted posts, which would hopefully promote more discussion, engagement, and new posts.