matrix_jan - 5:25 pm on Mar 5, 2013 (gmt 0)
From my practice marking 404s as fixed will just make them disappear for a short period of time. I still have thousands of 404s and 410s, and have no idea on how to "fix" them.
...because once Gwmt reaches about 50 errors the traffic drops off but the errors continue unless I remember to go into Gwmt to remove them. But soon as I remove them the traffic picks up within a week.
I saw that in the past. Errors in GWT definitely have something to do with ranking, hence traffic. And not only 404s, html improvements too.