Keyword Meta tag is no more an issue to concern about for new bloggers and webmasters as Matt Cutts (Google Software Engineer) clearly states in his video that Google does not use meta keyword tags for search engine ranking.
Why meta keyword tag being not used for search engine ranking?
About a decade ago, Google use to decide the page relevancy to place it in search engine based on the contents of the page. So, keywords or keyword meta tags were being much abused to their extent to manipulate the search engine rankings even if the page does not have any relevancy with the search keywords. Hence many years ago, Google started dis-regarding the keyword meta tags for search engine rankings. Google now much depends upon several off page factors too for setting the page relevancy and positioning any page at the top of search engine ranking.
Read the official webmaster guide for what Matt Cutts is saying about meta keyword tags by Google Search Engine
So, it’s really a bad idea to waste time on keyword stuffing in meta keyword tags. So, try to spend time on some White hat SEO techniques instead of keywords in meta section.
