I have about 960 pages indexed in Google. Recently I received 2 alerts of "Increase in Not Found Errors: 404" in Webmaster Tools, first on Oct 12, 2013 in which 25 Errors were reported while second on Oct 19, 2013 in which number of error are increased to 37 Errors.
Since yesterday I've observed sudden drop of approx. 70% in my website traffic. Following are last 7 days stats:
Oct 14, 2013: 83 Visits
Oct 15, 2013: 103 Visits
Oct 16, 2013: 106 Visits
Oct 17, 2013: 107 Visits
Oct 18, 2013: 94 Visits
Oct 19, 2013: 24 Visits
Oct 20, 2013: 27 Visits
While reviewing errors list I found that last month I removed some categories from my website which resulted in generating 404s against deleted category pages.
In your opinion, do you think that it is the main reason of this drop? What is the solution?