Extraordinary growth. How does it look on other metrics; e.g. numbers of posts and comments? Also, can you tell us what the growth rate has been per year? It's a bit hard to eyeball the graph. Thanks.

I'm generally in favour subdivisions, but there are many ways of doing it. E.g. you could have literal subforums, or just have more ways of sorting things. One idea is to split karma into subcategories. Get rid of karma as an indicator of "overall quality" of posts, and instead split into something like "quality_1", "quality_2", "quality_3", and have buttons for each category. The qualities could be any of "novelty", "altruism", "community", "urgent", "concise", etc.

The point is that karma can only capture something like the weighted average of the various qualities a post has to offer, and the more quality-dimensions posts can vary on (and the more people vary on what they care about), the more you gain from splitting the ranking system to start capturing several subsets of quality individually. Now people who care about varying dimensions of quality have an easier time self-matching to posts that score high on the dimensions they care about. It could potentially increase the both the quantity  and diversity of what people read, due to high-variance strategy/market segmentation.

Another consideration in favour of such a system is that overall-quality karma can exacerbate suboptimal incentives. People want to "stay in the loop", so they read things in order to not feel left out of the discussion. And overall-quality karma generates stronger signals about what's "in the loop" than split-karma would. This is bad insofar as it skews people's reading incentives from what's optimal.

Great work with the growth! I like the new ideas, and I am excited to see more improvements on the forum.  Good luck with the hire.

Off-topic comment as usual: that "about the author" block is really cool, how does one do that? Can we just have them for every post or something?