Long tail keywords is a term you will often come across in SEO circles, and basically refers to the less popular keywords that get fewer searches per month in the search engines, but are easier to rank highly for, because there are far fewer sites competing for that term. In short, they can be the difference between getting little or no traffic, and getting hordes of traffic to your website.

Let me explain in more depth why they are so important.

If you think of each keyword as a potential doorway into your site from the search engines, then obviously the more keywords you are optimizing your site and it's respective pages for, then the more traffic you should expect to receive.

That's correct in theory, but the reality is that if you are optimizing every page of your site for the most popular keywords in your niche, then even if you are heavily optimizing your site, you are still looking at many months before you start ranking anywhere near the top of the search engines.

So while you should target the most popular keywords in the long-term, you have to think about getting traffic in the immediate future. This can be best achieved by targeting the less popular keywords that have far less competition in the search engines.

You can use any number of keyword research tools to discover these keywords and phrases. They are usually between two and five word phrases long, and as I've already mentioned have far less websites competing for that particular phrase.

So what you will want to do is to find a popular keyword that you want to rank highly for for every page of your site, but also look for three or four of these long tail keywords or phrases, and focus on optimizing for these terms initially. This way by adopting the usual SEO methods, and having a good internal linking structure, you will start attracting traffic from the search engines to numerous pages of your site from these various different long tail keywords.

That basically explains why long tail keywords are so important in relation to SEO, but I should also point out that these longer terms are also good selling terms, and therefore convert very well. This is because these longer terms often better convey exactly what the searcher is looking for.

For example, let's say your site collects leads for a particular dentist in San Diego. Now a page optimized for the term 'San Diego dentist' would obviously have very high conversions, whereas a page optimized for the broader term 'dentists' would receive a lot more traffic (if ranked highly) but would see minimal, if any conversions. So this is another reason why you should target those long tail keywords.

This also ties in with pay-per-click advertising because while most inexperienced advertisers will target the highly searched broader terms, the advertisers who are cleaning up are those bidding on the long tail keywords that get less traffic, but are far more targeted and have far less competition.

So to conclude, if you have any kind of website and are only optimizing your site and it's respective pages for the most popular, and most competitive search terms, then you are missing out on a lot of free and targeted traffic from the search engines. This is equally applicable to pay-per-click advertising, so the importance of long tail keywords cannot be underestimated.