Long-tail keywords are specific, topic-related phrases that accord to niche markets.
They can be broken up by a full-stop or a comma and can even spread across several sentences.
They are definitely not a new concept. Long-tail keywords have been around for a while, but it’s only recently that SEO marketers have begun paying attention to their utility.
The reason for their resurgence in SEO marketing is mostly due to Google’s Panda and Penguin updates. Google is now scrutinising the quality of all website link profiles; webmasters are accordingly going back to long-tail keywords because of this.
Long-tail keywords work better than short ones for a variety of reasons. They account for a very large proportion of search traffic and more importantly, there is far less competition for the keywords involved.
It’s true that the search volumes are less, but if a more specific set of keywords is targeted, they will be more successful than short, high-competition keywords.
The other advantage of using them is that it greatly enhances the chances of someone actually being interested in the advertised product, content or service if they search for that particular string of keywords.
One should take care to avoid abusing long-tail keywords, however. A sign of bad marketing is when a writer tries to shoehorn at least five instances of the keyword phrase into the article. Search engines are now smarter in the way they review such articles, thanks to updates like Panda and Penguin.
You’d be better off giving search engines smaller mentions of the keywords, rather than overloading and inundating the content with them.