This document discusses how display advertising is evolving from mass targeting to highly personalized targeting using big data. It introduces myThings, a company that uses conversion data to personalize ads for retailers. MyThings uses various data sources like CRM, social media, and on-site behavior to segment audiences precisely and serve unique campaigns to each segment in real-time. A case study example with Littlewoods is shown where combining 1st party data and retargeting led to high ROI. The document argues that while big data presents big opportunities for retailers, many are unprepared to leverage it for advertising.