Programmatic buying uses real-time data and technology to customize advertising to meet advertisers' needs. It allows for bidding on millions of ad impressions across different exchanges and platforms. Data such as bid price, exchange, ad size, language and noticeability are recorded. Predictions are made on conversion rates and are adjusted based on positive or negative signals from impression and click data. The goal is to understand all factors that influence sales like channel, site, user demographics and purchase intent in order to optimize tactics across different stages of the customer journey from awareness to acquisition.