Long tail keywords are the primary three or four keyword phrases that are very specific to your product, service or industry.
Long tail key phrases are unique to what ever it is that you are selling, and have a higher chance at giving you a sale.
Another easy way to look at long tail keywords literally, is too look at them like the long tail keyword dinosaur. Meet Mr Long Tail Dinosaur.
His head represents the ‘high’ search volume keywords, the body represents the ‘medium’ average search volume, and the tail represents the smaller search volume, (but very specific to your audience to your) niche.
Thus the name for long tail keywords.
The tail is what brings you paying customers that convert easily. They are searching for a very specific thing.
This is what we call in the SEO world ‘unique knowledge’. Long tails keywords usually come from unique knowledge.