The very first thing I did when your URL loaded was to increase the browser text size. A good rule of thumb when it comes to typography on the web these days is to be very cautious about setting a font-size smaller than the usual 16px browser default.
If the content is very short (like comments on HN) then I don't mind the long lines though.
And small fonts are definitely a problem, I have set my browser's minimum font size to make HN more readable :)
* I love the font size and content column width. More line height than 140% might be good, but I then again have extreme preferences for line height (160%).
* Consider not paginating the posts, or picking a higher limit. You currently have 1 more than you show on the first page, so why not show it on page 1?
* The big image on the search page is funny, but takes a very long time to load. Removing it or moving it to a CDN will make loading that page faster.
* text-align: justify is your friend! Thin columns look weird with right-aligned text.
Admittedly, my site is not a blog but long-form content, which makes me wonder how well my results might generalize.
* Was that test just on new users - or subscribers in general? If the latter you're going to self-select for folk who are interested enough in your stuff to read regardless, which will skew the results somewhat.
* Also - judging by the blog topic - you've got a pretty technical audience. One of the few groups that do have the knowledge to use tools and preferences to get around the problem. I'd be leary of generalising that to other markets.
* You're a/b testing on max-width setting - not line length. So a bunch of your users in both groups are going to get exactly the same experience if they're on smaller displays. This will make the improvement on larger displays seem less significant.
* Tests like this can be really skewed if you have audiences that shift device over time (e.g. getting popular link tweeted and retweeted can push sometimes push up the mobile portion of a site enough so that certain display types work better/worse.)
* The line length is something that has interactions with other typographic features like line spacing and font size. Optimising on one alone can lead to poor results.
I'm not saying that you're wrong - but those are things that occurred ;-)
In general what the research done by others indicates is that users prefer shorter physical line lengths, but read faster on some longer line lengths (within limits obviously - backup http://www.usability.gov/articles/newsletter/pubs/082006news...)
I don't have 'subscribers' or 'new users'. Just people visiting the site. (I suppose there's people visiting from the RSS feed, but they're well under 1% of page views.)
> you've got a pretty technical audience...I'd be leary of generalising that to other markets.
OP's blog seems rather technical.
> This will make the improvement on larger displays seem less significant.
True, but this still wouldn't explain why the smaller max-widths - the max-widths that would hit the most viewers - would not win.
> * Tests like this can be really skewed if you have audiences that shift device over time
Certainly, but the 2 tests were separated by something like a year. Is it really likely the audience changed in both a/b tests in the same way?
> * The line length is something that has interactions with other typographic features like line spacing and font size. Optimising on one alone can lead to poor results.
Sure, but in the absence of any specific reason to suspect an interaction...
* Wow... that type is small (zoom to 125% - something that I know that the vast majority of users do not know how to do)
* Wow... those lines are still too long for an easy read (zoom to 200% - which gets line length sane for me, but the font size is now huge and killing lots of my vertical real estate)
* God damn that fixed header is annoying and cutting into my already limited vertical real estate as I scroll
* Hit close or the readability button.
However, I do have an bigger footer, because after reading an article the reader should have various options like reading more of my articles, comment via email, flattr me, etc.
I also want a date on every article.
The titles on your overview page are hard to scan, because of the dates in front of them. I put the dates after the titles and dimmed them down.
I'm aware that many people hate light-on-dark, and I'm trying to find a solution that makes both me and such users happy.
Also, try resizing it or viewing on a phone.