META-keywords are very often misunderstood and misused. Some webmasters put hundreds of keywords in this tag in the completely unrealistic hope of receiving good rankings for everything listed. Some webmasters even include keywords that have absolutely nothing to do with the actual web page or web site.
That has forced the search engines to lower the META-keywords importance in the determination of what a web page is about. However, some search engines still read and use the META-keywords. Thus, remember to write relevant META-keywords for all your web pages.