Ask HN: How often should you redesign your site?
Every year? Every 2 years? What do you think is the best combination of not being stale and not throwing money down the drain?
As for total throw-it-out-and-start-over redesigns: I'd say "seldomly". I did one once, because I had the golden opportunity for it -- both a major tech change that was going to require a code rewrite, significant technical debt in keeping up the old templates, and major feature modifications which forced a rethink of my information architecture. As long as I was going that far I figured, eh, what the heck, get it a totally new look as well.
I was surprised that for all the extra work added and the professional design, conversion rates moved less than when I tweaked spacing on buttons a little bit. Ahh well, that's the way the cookie crumbles. The non-design aspects of the relaunch proved worth their weight in gold.
(I was also totally prepared to send the designer a check and a thank-you card and not use a single pixel of it if the conversion rates changed in a majorly negative direction after the switch. Thankfully the starting hiccups were not that bad.)
[Edit: incidentally, sub-sections or mini-sites are a great way to beta a design against your visitors without having to put your existing relationships or numbers at risk. When I made sweeping changes to my site, the sweeping changes started out on a "brought to you by this other site" mini-site that I set up, and I did iterative improvement on things like button placement and calls to action over there before I integrated them with the oh-goodness-if-I-screw-up-this-will-cost-money site.]
If it's mostly content then I'd say constant small revisions with the occasional overhaul. Tweak to whatever delivers the content best.
It's different for a functional site. Even if a tweak is an usability improvement, existing users will go "eh?" when you (say) move a button. If you did this too often it would actually reduce your net usability. I'd say changes to this kind of site would be better aligned with every major feature release... With a major overhaul probably being a rare event.
Here's the thing. Your site should be in constant state of flux with new features added and subtracted, moved etc. After a while you'll just end up with a bit of code "crud". Its almost worth it just to do a site wide front end rewrite once every 3 years or so. I think 5-7 years is about the amount of time that it takes for a styles to change enough where your site will start to get a bit stale.
There are many dangers in redesigning prior to establishing a goal (particularly with commercial sites) -- principal of which is never knowing when and if you've succeeded.
I need to redesign my commercial sites, but I'm not sure what the goals of the redesign would be. Seems like if you have something that works (like Drudge) what's the point in redesigning? I guess having new goals -- changing market demographic, desire to keep it fresh, improving click-through or sales, etc -- is the most important driver.