Programmatic buying describes online display advertising that is aggregated, booked, flighted, analyzed and optimized via demand side software interfaces and algorithms. The share of ads bought through programmatic technologies in the UK is estimated to grow from 28% in 2013 to 60-75% of total digital display advertising by 2017. Programmatic buying has taken off because it allows for the automation of tasks like ad placement decisions based on user attributes and previous engagement, and makes every impression, brand lift, click, and conversion measurable in real time.