For many SEOs, keyword research is all about finding keywords with a high number of monthly searches and low competition. Some of the more advanced will move on to long tail keywords, or keyword phrases, or look to local keywords to help lower the competition and leap to the top of the search engine results page.
These are all great strategies, but to truly show your skills as a keyword ninja, and find those untapped gold nuggets, you have to know how to identify long-tail, LSI keywords.
What are LSI Keywords?
If you were to search for a definition to LSI, or latent semantic indexing, keywords you would find answers all over the map. Most people will tell you that LSI keywords are simply synonyms for your keywords. The belief is that by finding similar terms for your primary keywords you can make your content look a bit more natural while adding more possible search terms into the mix.
However, this rudimentary explanation of the term doesn’t do enough to serve our purposes. If you want to master the LSI keyword we have to get elbows deep in what it means. I wrote an article specifically for that purpose: “Latent Semantic Indexing (LSI): What is it, and Why Should I Care?”
Wikipedia describes LSI as having the, “ability to correlate semantically related terms that are latent in a collection of text;” a practice first put into use by Bell Labs in the latter part of the 1980s. So it looks for words (keywords or key phrases, in our case) that have similar meanings and words that have more than one meaning.
Take the term “professional trainer,” for example. This could mean a professional fitness trainer, a professional dog trainer, or even a professional corporate trainer. Thanks to LSI, the search engines can actually use the rest of the text in the surrounding content to make an educated guess as to which type of professional trainer is actually being discussed.
If the rest of your content discusses Labrador Retrievers, collars, and treats, then the search engine will understand that the “professional trainer” being referenced is likely a dog trainer. As a result, the content will be more likely to appear in search results for dog trainers.
Another case would be where multiple synonymous terms exist in the same piece of content. Take the word “text” for example. If this were a keyword for which you were trying to optimize your page, words like “content,” “wording,” and “vocabulary,” would all likely appear within the content because they are synonyms and/or closely related terms.
The benefits of LSI keywords
The most obvious benefit to LSI keywords is that your keyword reach becomes broader by using synonyms. As I wrote in my article “The Rise of the Longtail Keyword for SEO,” “they are playing an increasingly essential role in SEO.”
In addition to the broader reach, your content will rank higher in search engines because of the supporting effect of the LSI keywords. Repeating your keywords over and over throughout the text in an attempt to achieve the perfect keyword density (which, by the way, is a completely outdated SEO term and tactic) makes the content read awfully funny; and the search engines are smart enough to detect this sort of manipulation, too. Using synonymous keywords helps make your content a richer experience for the reader, and more legitimate (and thus, higher ranking) to search engines.
Finally, LSI keywords help keep you competitive for your primary keywords in the right context. If you are optimizing for the term “professional dog trainer,” you’re less likely to be competing against the other types of professional trainers in search results.
Great, how do I find LSI keywords?
The search for LSI keywords starts with your primary keywords. They are the foundation of your SEO efforts, so if you don’t have these identified yet, then go back and find these first. Once you have them you can get started with LSI keywords. How do you find primary keywords? See my article, “The Definitive Guide to Using Google’s Keyword Planner Tool for Keyword Research.”
Contrary to what you learned in high school, the thesaurus is not your first stop to find synonyms for your LSI keywords.
The easiest way to find out what the search engines think are terms related to your keyword are to use the search engines themselves. Go over to Google, and start typing your primary keyword into the search box. Note all of suggestions that are provided and you will not only have a list of related keywords, but a list of keywords that Google knows are related.
Once you’ve made your list, hit enter to perform a search for your keyword. Scroll to the bottom of the results page, and look at the Searches related to <your keyword>. This will also give you some insight as to good ideas for your LSI search terms.
Google’s Keyword Planner
There have been a few changes, other than the name, when it comes to Google’s new Keyword Planner, but anyone familiar with the old Keyword Tool should be able to navigate through it with no problems.
You can use it to find LSI keywords, and the process is simple. First, click on Search for keyword and ad group ideas and enter your primary keyword in the Enter one or more of the following box and click on the Get Ideas button at the bottom. On the following page, click on the Keyword ideas tab to get a look at not just a list of recommended LSI keywords, but their monthly searches, competition and other metrics that can help you decide which ones to target.
Paid keyword tools
Like anything else in SEO, there are plenty of software packages and services you can buy that will help you in your search for LSI keywords. The downside to these is that you are paying for something that you can get for free. The upside is that the training and support that comes along with most of these purchases will help you learn how to find these keywords more easily.
The secret operator
Actually, this is no real secret, but if you place a tilde (the squiggly line ~) before your primary keyword in the Google search engine, it will provide you with the results for synonyms to your search term; for example, ~professional dog trainer.
Reading over the titles and descriptions of the results, you’ll be able to find some good LSI keywords. If you want to leave a term out of the results, add that phrase to the query with a minus sign in front of it. For example: ~professional dog training –dog grooming.
Like your primary keywords, you need to make sure that you don’t over-do it when it comes to LSI keywords. A few closely-related terms will be sufficient to help your SEO efforts. And like your primary keywords, don’t try to insert LSI keywords into the text where they don’t fit.
Remember, latent semantic indexing will only help you if you are writing good content for your readers. LSI keywords will give the search engines the information and evidence they need to understand what your content is saying and reward you accordingly.
Want more information on content marketing? Head over to our comprehensive guide on content marketing here: The All-in-One Guide to Planning and Launching a Content Marketing Strategy.