Marketers don't spend in traditional media the same as digital media, so why would we treat these the same way in our model? We don’t.
ChannelMix defines our digital ad stock, or lagged effect of an advertisement, as 14 days. Traditional media, such as a billboard or TV, by design reaches a broader, less targeted audience with a more rigid cost structure than digital ads. Therefore, ChannelMix’s MIM trains this data separately with a more flexible ad stock to account for the differences in both cost structure and flexibility.
For example, if you purchase a billboard for two months, a 14 day ad stock will not account for the traffic. Instead, we use a two month ad stock (the time period of ad placement) with a standardly defined diminishing return.