It's clever, but is it useful?

Waypath has a tool called the Buzz Maker that will plot a graph using up to five different topics that illustrates (if I understand it correctly) how often the various chosen topics are mentioned in Waypath's database of 192,786 blogs. They even provide code so you can include said graph in your blog. I've tried it, but I can't quite figure out if Buzz Maker is useful or not.