tedster - 8:01 pm on Sep 12, 2012 (gmt 0)
3 long tails keys seem to bee affected all time.
Then we can throw that possibility out as an explanation for on-again off-again zombie traffic.
sudden start of "scrapping machines" like server***u.com
Does scraping traffic come in showing a Google Search referrer?
start of legal search engines ( yandex, some chinese engines ) scanning the site
Google can't be doing that. It sounds like your analysis has not focused on just Google traffic.
The zombie traffic starts with 10 min. with heavy zombie traffic and will slow down the day/next day. Following not converting traffic.
I thought we were talking about one thing here - traffic that does not convert - and calling that zombie traffic. The only other topic was "traffic throttling".