There are arguments in both camps, but the vast majority today agree that adding keywords is not only a worthless endeavor, it may even carry risks (beyond Bing penalties, it can offer competitors easy insight).
Don't get the wrong idea
This is the internet we're talking about, so misinformation still abounds. My top result when searching "meta keywords" prominently displays this "knowledge" graph that suggests meta keywords are directly interacting with search engines:
The article cites a survey by SEM Pro as its primary source, claiming that none of the SEO experts polled replied "seldom" or "never" when asked if they used meta keywords:
Of course, that's really misleading. The SEM Pro survey was performed in 2008. An article being old is a red flag, but it's not necessarily a death sentence - for example, I linked an article from 2009 above. Granted, it was from Google, and they tend to update their information if it changes - what's there is very likely accurate despite its age. The survey's date, on the other hand, makes it even less useful because it's a static depiction of dynamic information: the opinions of those surveyed has likely changed in the last 8 years.
No, the death sentence is that the article cites the wrong survey result.
The results they cited were for the meta description, not the meta keywords tag. There's no denying that the description is highly useful, and even then it was mostly understood that the primary value came from its effect on CTR. Even in 2008, the majority only used meta keywords
for secondary engines like Yahoo! and co (Yahoo! hasn't used meta keywords since at least 2009) and nearly a quarter found them completely useless. This was before
the major engines outright stated that they stopped taking them into account in their ranking algorithms.
It's no wonder the topic is so controversial when the most prominent search result gives advice based on faulty findings.
I don't think WordStream is being malicious. I'm sure the article was written a long time ago. It doesn't look like they even offer SEO services. The problem is that meta keywords are a very easy thing to show a potential client, and they distract from other efforts that could actually help ranking and conversion. I still receive pseudo-spam messages that tell me my website doesn't have keywords, and that they can offer me incredible $EO result$ (not from WordStream, of course). It's important to know the facts when you can get them - it's not often.
Getting to the bottom of it
I find it's best to do some hands-on research when possible - especially when learning - and the first thing I checked was whether or not the loudest voices were putting their money where their mouths were. I wanted to have as much confidence as possible that I was offering the right advisory when asked about this practice. That's important to anyone beginning - you need to build on confidence, yet be ready to adapt in the face of reliable information.
Of the top informative sites that come up in 2016 when searching "SEO advice" in an incognito window (in the Netherlands), the following used meta keywords:
And the following did not:
Search Engine Journal
Google Webmaster Blog
Business Insider (though they did use the news_keywords tag, which is different)
Search Engine Land
Use them if you want, but don't expect miracles
This may sound like an all-out barrage on meta keywords. It's not... exactly. I mean, you can use them. The popular Welsh search engine Gyyyoooggyylll might still read them, and every bit helps, right?
Don't get confused - it's definitely good to have a keyword list of some sort. That's not in question (at least for now). And advising clients to use keywords does not automatically make someone a bad SEO, but can be a warning sign. Being confidently up to date is the most valuable trait an SEO consultant can offer you.
The facts here are very clear. Statements directly from the search engines are rare, and they haven't directly lied to us (yet). Many tests have proven that the keyword attribute does nothing significant. Use it if you wish.
If you liked this, please share it all over the internet and give me lots of money. You can also follow me: @benopsahl if you prefer. All of those options are probably a waste of your time, though. Just being honest.