Meta KeywordsTag Defined
About SEO > Meta Description Tag
Meta Keywords The Meta Keywords tag is considered by Google to be a useless tag which is not considered to be a Ranking Signal. Some SEOs commonly don’t believe all of what Google states publically and they therefore include relevant terms in the Meta Keywords tag. Some believe that it is not considered but include it in case that changes while others use it for other Search Engines to consider.
Optimizing your Meta Keywords tag:
As Search Engines are becoming more and more focused on Linguistic Semantics which means they wish to provide results based more on the intent of the searcher and not just the keywords used. It is therefore good to put in only keywords which are specific to the page’s topic. Another great area to include keywords is by using Schema.org markup and structured data in your Meta Description tag.