The quote from Steve Jobs will clear all the ambiguity in your mind and thus start saying 'No' to live your life to the fullest extent.
We have applied this formula to our stock research advice and while providing the stock tips we have to go through a plethora of data and we learnt to say 'No' to trash to be concentrated towards our primary business and we even turn down advertisers who want to pay us by allowing them on our website as we do not want to spoil the user experience with all those funky popping ads.