The part that TechCrunch left out was that the idea for MixRank started as an Offer HN post(remember those?) where 150 startups asked me for marketing advice: http://news.ycombinator.com/item?id=1839163
I realized that I was giving the same basic suggestions over and over again, and wanted to productize and mass produce strategies for building successful paid traffic campaigns- which usually involves doing market research and figuring out what's currently working in the marketplace.