From 2009's Paul Graham opus, "What I've learned from Hacker News":

February 2007: 1600 daily uniques

February 2009: 22k daily uniques

July 2012: 150k daily uniques

Paul Graham says bad comments are a harder problem than bad submissions:

There are two main kinds of badness in comments: meanness and stupidity. There is a lot of overlap between the two — mean comments are disproportionately likely also to be dumb — but the strategies for dealing with them are different. Meanness is easier to control. You can have rules saying one shouldn't be mean, and if you enforce them it seems possible to keep a lid on meanness.

Keeping a lid on stupidity is harder, perhaps because stupidity is not so easily distinguishable. Mean people are more likely to know they're being mean than stupid people are to know they're being stupid.

Today Paul Graham wrote about that 2009 article:

It's remarkably close to what I'd write today. The biggest difference now is the numbers. Now on a typical weekday we get about 150k unique IPs and 1.5m pageviews.

Compare HackerNews' 45m monthly pageviews with Reddit's 2 billion.

Quora surmises that Reddit's high pageview count is due to people refreshing pages.

These are very insightful points. Content moderation is challenging and interesting problem, which requires a lot of skill and balance. For example smart mean comment might be valuable negative feedback expressed in mean way to strengthen the message. I would not imagine stupid comments would ever be valuable, but detecting the stupidity is difficult and subjective task.

I think, it might become an application of Sentiment Analysis. There should be an algorithme to automatically 'flag' mean comments. Not sure is automated moderation will be possible in near future, but flagging comments for further review by human moderator should be possible.

If anyone was going to try to automate the removal of stupidity and meanness, it would be Paul Graham.

You think he can shut down FOX news?

If anyone can, it's Paul Graham. :)

The reddit stats you linked to say 13 page views per visit and average time on site of 16 minutes. That does not sound like pointless page refreshing.

The main numerical difference between them and Hacker News is that while they have a very obvious demographic skew they seem to be in the middle of escaping from the geek culture ghetto that HN and Slashdot had no interest in escaping, and Digg failed to escape.

The list of subreddits by popularity http://redditlist.com/ shows a geek bias but the highest geek specific topics are "Gaming" at rank 7 and "technology" in rank 14.

All excellent points. Thanks for the data, Luke.