I love BuzzSumo! They also have fantatic webinars with ideas about how to further use their product to do competitive research, come up with new topics, find influencers, etc. "For example, if you notice that posts about a new keyword research technique are trending across several sites, you could write another post on the same topic to jump on the gravy train. Alternatively, you could pick the popular posts apart, find their weaknesses and then go away to create a killer post which will wipe the floor with anything currently out there" I will say that (in my opinion) the latter use case you mentioned is a better use of time than the first. Even when writing high quality content, it is difficult to stand out amongst a sea of the same. I think it is always a better idea to uncover an angle of a trending/important topic that others either haven't covered or haven't covered in-depth and write from that angle. Just my two cents :)