In the “old days” shoving your web page full of irrelevant keywords or "Key Word Stuffing", used to help drive it up the search engine listings.
This allowed websites to be listed for content that really wasn’t on the website at all. A good example of this would be listing every town and county in the footer of a website (seen that too many times).
If you don’t have an article or a specific page about the town or better still an office in a town, then you can’t simply list the town name and hope you are found under the key word. We can’t create a page with a list all towns in the UK and hope we get at the top of the listings for “Web Design Edinburgh”. The truth is we don’t operate in Edinburgh (though we would love too).
The Google algorithm isn’t simple or stupid. It will recognise the use of key words and how they are constructed in a sentence. If that sentence is “real” and is useful to a visitor then it will be indexed appropriately.
If the overuse of keywords creates a negative user experience then it’s likely that the page will not be indexed, or worse, it may get your website demoted or blacklisted from Google.
It’s not rocket science… Provide good quality prose that is relevant and useful to the user on your website and watch your listings improve.
Want to read more about “Key Word Stuffing” from the kings of SEO then visit Googles page on irrelevant keywords.