i tried google webmaster and:
Cloaking and/or sneaky redirects
i use 2 pop-up advertise, and many plugins..
possible pop up advertise?
These are the good methods for increasing traffic but if the traffic has been lost from google then I must suggest you to check your analytics. Analytics is the best way to analyzes your website. I think this will surely help you to know where your traffic has lost.You try to post unique content in blogs and articles its helps better to increase traffic to web site and also generate back links.