bhartzer - 5:01 pm on Mar 21, 2012 (gmt 0)

incrediBILL, most likely the domain was owned by a domainer that owned tens of thousands of domains--and therefore didn't have the time to focus on domains that weren't hugely profitable.

why 200 OK as a result code for a link checker turned almost useless for external links.

Maybe it's about time to build a better link checker, huh? Personally, I use a spider that allows me to input a list of URLs to spider(check) and it grabs the title tag and other meta data of the page, as well as the server header info. I can easily see which ones are gone.