Long tail keywords are words or phrases that are a bit obscure in terms of internet traffic search request.
If “free ringtones” is a good keyword then “free Michael Jackson ringtones for iphone” is a long tail keyword.
There is less competition for the long tail keyword, and also less traffic. So it’s a gamble as to if it is going ultimately pan out or not.
The phrase “content is king” comes to mind when talking about long tail keywords. While 1 long tail keyword page would mean very little traffic. 1,000 long tail keyword pages could mean some serious cash. Just something to think about.
If you write enough content then you are bound to get some decent traffic, assuming this is quality content.
Why are they called Long Tail?
Most likely because of the fact that if you plot them out on a graph they are the obscure terms at the very far right bottom of the curve. That curve looks like a very long tail. (i may be wrong, but that makes sense to me)