Long tail key phrases
Long tail key phrases are a great way to optimise pages. The likelihood of somebody who visits your site from getting that keyword phrase are buyers instead of researchers, for example - somebody typing in 'high definition television' would be looking to buy a high definition television but doesn't know which make or model to buy so they will go through a number of web sites researching which would be the right television for them. If your long tail search was 'sony KDL-46BR3 high definition television' then the likelihood of that person who is searching for that key phrase has done their research and is now ready to make a purchase. Finding a niche term can help the profitability of your site with ROI (Return On Investment) but research must be done to check competition from other sites.
Unfortunately re-writing your page with a longtail key phrase in mind doesn't work with the results you may require. A number of techniques must be implemented to get to the longtail phrase.