The Long Tail or long tail refers to the statistical property that a larger share of population rests within the tail of a probability distribution than observed under a 'normal' or Gaussian distribution. A long tail distortion will arise with the inclusion of some unusually high (or low) values which increase (decrease) the mean, skewing the distribution to the right (or left).

The term Long Tail has gained popularity in recent times as describing the retailing strategy of selling a large number of unique items in relatively small quantities – usually in addition to selling fewer popular items in large quantities. The Long Tail was popularized by Chris Anderson in an October 2004 Wired magazine article, in which he mentioned Amazon.com and Netflix as examples of businesses applying this strategy.Anderson elaborated the concept in his book The Long Tail: Why the Future of Business Is Selling Less of More.

So what does this all  mean?

Many bloggers and online publishers are obsessed with being on page one for a certain keyword, and they forget about the Long Tail.  I have a client, a plumber, who wanted to be on Page One of Google for BEST CHICAGO PLUMBER. And we got him there. And he gets about 50 hits a month  for that word.  But his Long Tail, he gets over 300 hits for about 250 keywords! That is the long tail in action!

One recent study shows that even if your site is optimized for the top 100 keyword phrases in your niche, you are still missing 94% of the people who are searching for what you have to offer.

The reason you're missing so much potential traffic is because most people don't search for short keyword phrases. They search for what is called long tail phrases.

Below is a quote from Wordtracker that shows how valuable long tail
keywords are:

"Bill Tancer, general manager of global research at Hitwise,
revealed that for any given topic, the top 100 keywords account for
just 5.7% of all website traffic - while long tail keywords account
for the remaining 94.3%!"

One big advantage of long tail keyword phrases is that they include the short phrase within the long tail phrase, so you're getting two birds with one stone.

Another big advantage of optimizing for long tail keyword phrases is that when someone searches using a long phrase, they are describing exactly what they want and they are ready to buy.

Bottom line: Write and post more pages of text on your website (at least, one new page a week).
Have a unique keyword-rich Title tag for each page and have 300 to  500 words of high-quality, keyword-rich text on each page.

Do this and you could soon see 10  times more visitors to your site -- and these will be highly motivated viewers.