Google filters

Search Engine Marketing, Search Engine News, Blog Search: "Google recently introduced a new keyword phrase filter during its most recent update. Some phrases were unchanged, but many highly optimized and highly competitive phrases were drastically altered. Some webmasters saw their sites drop from top listings to not being in the top 1,000 sites. Unlike other filters, this spam peanalty does not affect a page or sites overall perceived value. The end effect is lowered rankings for various specific searches for that page."