Google is continuing to improve page rankings through carefully examining the use of keywords within page content, including how many times a page is changed (through fine tuning web pages for seo)
In recent times, Google have downgraded websites for improving seo, but only temporarily if the keywords remain for a period between 1-4 weeks. For those optimising web pages who bottle it and change the content back – this is likely to indicate to Google some manipulation is involved and downgrade the web page even further (and for a longer period)
There is nothing wrong with optimising web pages, but you need to do it in a very simplistic way and leave the web page settle over a period of weeks, rather than days.
Also – it is still very common for website owners to stuff keywords in page content and meta data (often under keywords area in cms systems)
Stuffing keywords into a page and/or meta keywords field, will, sooner or later result in a downgrading amongst google serps (search engine results pages)
Both seo specialists and website owners alike will need to take a much cleaner and simpler approach to improving optimisation in the future to avoid poor results.