---- GWT swimming in 404 errors making it almost unusable
lucy24 - 11:11 pm on Dec 1, 2012 (gmt 0)
Once Google sees 410 Gone, they don't come back for many months to check the status again.
Necessary disclaimer: This applies specifically to google. Other search engines-- assuming for the sake of discussion that there exists such a thing-- may behave differently. This is based on direct personal observation. There are probably additional factors involved.