Choosing Tag line is an important thing…Most of time it is selected depending upon the type of story or on any strategic basis??? so I want to ask on what basis you people select the tag line??? and what directions you can give for selection of a good tag line???
tons of thanks 
I agree, with you, ALex, but with an exception. If you have in the tag line some strategic key words, most searcheable, Google will find you faster.
And to answer to NewGenMarketing, if you have a catchie tag line you’ll capture people’s attention and they’ll read you. You may search on the internet about what words are power words and to which brain reacts instantaneous and use them; but of course, to be related with the content.
Contrary to what you may think, tag lines are NOT important… the web has become so saturated with brand names, the need for a tag line has become redundant as people only care about the who, not the what. Do you remember Google for their tag line (Do no evil), most people don’t… it’s that simple.
Tag line will have a powerful impact in audience if you can create a remarkable phrase. So you will need to do some research on your topic that best fits your audience attention to create a compelling tagline.
can you define what you mean by “tag line”? - that can mean many things…