Spidering and organic activity are bundled together in this 66% number. It would be interesting to know what percentage of this was people who wanted to see an Onion page.
The spiders and organic visitors should have been 301 redirected to the correct location. Spiders learn the 301 redirects, and some of their articles may even benefited from better search rankings.
These hits will never (and should never!) translate into even a single real user in my case.