If the majority of the users were returning visitors, I wouldn't be concerned about the bounce rate (but then I'd have to wonder why the site wasn't getting new visitors.) If I felt the front page did a good job of putting something awesome in your face (instead of hiding it behind a link) then I wouldn't be concerned. If the sitepoint graph showed the site growing as quickly as 50% new users per month implies it could, I'd assume the bouncers were returning visitors. It's that combination of factors that makes me think that new visitors are going away and that the web marketing has room for improvement.
A lot of blogs have only a single page - that single page nature may be why they've got a higher bounce rate compared with other types of sites because new visitors get the content they were looking for on the first page, and because there's not anything else to do but read. Yes, you can read every post if it's really interesting (Hyperbole and a Half was like that for me.) but 90% of the time I'm just grabbing a recipe real quick or trying to figure out how to fix my blender and the information I need is right on the first page, then I'm done. These single page blog sites aren't a gateway into a community. And LessWrong isn't a place with practical information where you're doing a quick question run. Correct me if I'm wrong, but this place attracts intellectuals who love reading. Assuming that's the sort of person coming here, we have to ask why new visitors are not clicking. It's not because they're satisfying their reading fix on the front page as with a single-page blog. The front page doesn't have a lot of text. If they have an intellectual nature, and are expecting to read something interesting, they should be showing more curiosity about other pages. That they're not means the page failed to interest them. Why else would a new visitor leave without clicking on something when you think about the current home page design?
When it comes down to it, there's no right number. Every website and situation is different. You can find people saying "oh 60% is normal" and other people saying "60 percent! You should be worried!" but when it comes down to it, it really depends on the situation.
And then, you also have to ask yourself this:
Do I want to tell myself my bounce rate is okay or do I want to get as many repeat visitors as possible?
If it's the former, 60% is okay. If it's the latter, especially if you've got that many new visitors not becoming returning visitors, 60% is totally unacceptable.
Good marketing techniques can bring the bounce rate down to 30%. Can they do that for this website? I don't know. I say that it's time to make a hypothesis about what would work and do the experiment of trying it out.
If you would like a reputable source of information on this, you can try this Google video. I assume they know what they're talking about because they probably profit off of helping website owners make their websites better, since a lot of those people use their adwords service on their websites - I've been told they care quite a bit about profiting off of that:
http://support.google.com/analytics/bin/answer.py?hl=en&answer=1009409
How do I know this? I got a copy of the website analytics.
The bounce rate for LessWrong's home page is 60%!
To be clear: Over half the people who visit LessWrong are going away without even clicking anything.
Yet how many NEW visitors are there? Almost half of the visitors are new!
Granted, new visitor statistics aren't perfect, but that's a LOT of people.
Simple math should tell us this:
If we got the bounce rate down around 30% (a reasonable rate for a good site) by making sure every visitor sees something awesome immediately, AND make sure that each visitor can quickly gauge how much they're going to relate to the community (assuming the new users are the right target audience), it would theoretically double the rate of growth, or more. There's a multiplier effect if the bounce rate is improved: you get better placement in search engines. Search engines get more users if they feel that the engine finds interesting content, not just relevant content.
It's been argued that it's possible that most of the bounces are returning visitors checking for new content. Well if half the visitors to the site each month are new, and we did a wonderful job of showing them that LessWrong is awesome, then the amount of returning visitors could double each month. We're getting a tiny, tiny fraction of that growth:
http://www.sitemeter.com/?a=stats&s=s18lesswrong&r=36
Why did I write you guys so much in the home page rewrites thread? Because I am a web professional who works with web marketing professionals at my job and to me it was blatantly obvious that there's that much room for improvement in the growth of LessWrong. Doing changes like the ones I suggested wouldn't even take long. Because I like this site, and I knew it had potential to grow by leaps and bounds if somebody just paid a little bit of attention to real web marketing. Because I was confused when I first found this site - I had no idea what it's about, or why it's awesome. I closed the home page, myself. Another friend mentioned LessWrong. Curiosity perked up again. I came back and read the about page. That didn't make things clearer either. I left again without going further. Friends kept telling me it was awesome. I came back one day and finally found an awesome article! It took me three tries to figure out why you guys are awesome because the web marketing is so bad. The new proposals, although they are well-meaning and it's obvious that John_Maxwell_IV cares about the site, are more of the same bad marketing.
I've been interested in web marketing for ten years. It's a topic I've accumulated a lot of information about. As I see it, the way these guys are going about this is totally counter-intuitive to web basic marketing principles. They don't even seem to know how harsh users are the first time they see a new website. They tend to just go away if it doesn't grab them in a few seconds. They're like "well we will put interesting links in" but that's not how it works! The links don't make the site interesting - the site has got to be interesting enough for users to click the links. Thinking the links will make the site interesting is backward. If you want to improve your bounce rate, your goal is to be awesome immediately in order to get the user to stay on the page long enough to want to click your link. If it wasn't usually hard to get users to click links, we wouldn't track bounce rates. These guys know this particular group of users better than I do, but I know web marketing principles that they're not even seeing when pointed out. To me, they seem to be totally unaware of the field of web marketing. The numbers don't lie and they're saying there's huge room for improvement.
If you want to grow, it's time to try something different.
Here's a thought: There is a lot awesome content that's on this website. We need to take what's awesome and make it in-your-face obvious. I wrote a plan for how to quickly find the most effective awesome content (the website statistics will tell you which pages keep new visitors on them the longest), and how to use them to effectively get the attention of new users - copy the first paragraph from one of those pages, which was most likely constructed by a competent writer in a way that hooks people (if it's keeping them on the page then it's essentially proven to!) and place that as bait right on the front page. (There is also a wrong way to do this.) Then of course, the user needs to find out why the LessWrong community might be a place where they belong. I shared ideas for that in "About us - Building Interest".
Don't let's assume that growth is going to be good. You're going to get more internet trolls, more spam, (there's a way to control spam which I would be happy to share) and more newbies who don't know what they're doing (I provided some suggestions to help get them on track quickly, preventing annoyance for both you and them). There will be people with new ideas, but if the wrong audience is targeted... well. We'd better choose what audience to target. I saw an internet forum take off once - it seemed to be growing slowly, until we looked at the curve and saw that it was exponential. That of course quickly turned to a dazzling exponential curve. Suddenly the new users outnumbered the old ones. That could happen here -- even if we do nothing. YOU can get involved. YOU can influence who to target. They're taking suggestions on rewrites right now. Go to the thread. I invite brutal honesty on everything I wrote there. Or pick my brain, if you'd prefer.
What do you want, LessWrong? Do you want to grow optimally? Who do you want to see showing up?