• At each stage in a consumer's journey toward purchase, different online channels feature most prominently.
  • Existing credit-assignment methods, such as the last click, suffer from the problem of attribution— they do not take into account the impact of all those advertising formats that were visited by a consumer contemplating a purchase.
  • Four rule-based models can be used for measuring the performance of an advertising campaign— the last-click, time-decay, uniformly distributed, and position-based models.
  • Multichannel attribution models have evolved to reflect the growing complexity of attributing credit with each new advertisement format.


Early academic research into attribution modeling mainly focused on click-through rates as an effective measure of performance (Ansari and Mela, 2003). Digital advertising soon faced a conundrum, however; several studies conducted during the early 2000s reported that click-through rates in fact were declining fast (Manchanda, Dube, and Goh, 2006). Researchers discovered that only a small proportion of visits translated into final purchase (Chatterjee, Hoffman, and Novak, 2003).