Question: We spend a lot of time optimizing our descriptions and keywords. We think we see an improvement when they are better optimized to suit the keywords on our site. But do they actually matter for the purposes of SEO?
The “keywords” meta tag has existed since 1995, when it was used by the first generation of search engines, such as AltaVista. At the time, the keywords meta tag was used as a self-reporting method of search query relevancy. It was most definitely useful back then, but it’s easy to see why this type of tactic doesn’t work (or exist) now.
As of 2009, we can be certain that Google no longer takes into account the “keywords” meta tag. Yahoo still indexes the “keywords” meta tag, but gives it the “lowest ranking signal in our system.” You might be inclined to think “Well, that’s still something,” but it’s really not — the ranking signal is lower than just putting the keywords in the text of the site. So it’s basically worthless.
What changed with Yahoo’s ranking algorithms is that while we still index the meta keyword tag, the ranking importance given to meta keyword tags receives the lowest ranking signal in our system…. it will actually have less effect than introducing those same words in the body of the document, or any other section.
Further, some point out that including your keywords directly in your site will give your competitors insights into the general thrust of your advertising campaign. If you’re running a campaign based primarily on the keyword “custom 3D printed widgets,” a competitor could buy you out of that space without having to guess.
As for the meta description tag, it does nothing for SEO — but it may be displayed on the search engine results page, so it still has value. Descriptions should be carefully written for user comprehension, rather than search engine optimization. In other words, it should be human-optimized rather than search engine optimized.
Of course, the meta description tag isn’t always displayed on the SERP; Google tries to generate a result that is most useful to the user, pulling from a variety of sources, including both the meta description and the page content.
Answer: No. Meta descriptions may be displayed to the user but does not affect SEO — keywords should be avoided. The meta keywords tag does nothing on Google and almost worse than nothing on Yahoo.