I assume the drop was in search referral traffic - did specific keywords get hit more so than others? If you're whole site has been penalized, you should see th

I assume the drop was in search referral traffic - did specific keywords get hit more so than others? If you're whole site has been penalized, you should see the affect across all your keywords. Also check out webmaster tools for more insight - https://www.google.com/webmasters/tools/home?hl=en https://www.google.com/webmasters/tools/home?hl=en