1) The document discusses using online consumer behavior to identify target groups with purchase behaviors and serve them targeted ads as they browse Yahoo to measure the impact on offline retail sales. 2) A four step process is outlined: segment consumers, develop a purchase model, serve ads to targets, and analyze sales impact. Testing showed a 14% sales uplift and $0.52 average difference for exposed vs unexposed buyers. 3) Over 400 programs have run so far, averaging a 31% short-term sales uplift and $2-$5 ROI for every $1 spent. The biggest driver of incremental sales is targeted reach rather than click-through rates.