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They need it if they are exact duplicates or highly similar. It is not used for pages that just have the same keyword but are otherwise different.

Hi Jon, I have just checked this URL : http://ideas.salesloft.com/forums/140374-general/ , there buttons of hot, top, new to filter it out. In this canonical implementation is the best solution in your case. Put canonical tag in hot,top,new page for original URL which is http://ideas.salesloft.com/forums/140374-general/  in above case.