Hello everybody. I own niche websites network. I have like 100 sites already, all sites are EMD (exact match domain). After google released their new rules about "overoptimized sites" my sites began falling at ranking position. I began building new backlinks, add new content...everything were useless. After that I tried delete Google Analytics from all my sites and change title (like [product name] + review), and left site for 1 week. After a week all my sites ranking again and bring me good revenue (I get all money from adsense). May be a coincidence, I'll never know. BUT I WILL NEVER USE GOOGLE ANALYTICS AGAIN.