The effectiveness of high-frequency direct-response commercials

To optimally schedule commercials for a car repair service, we investigate the impact of direct-response commercials on incoming calls at a national call center by using a unique hourly data set from a Belgium-based company. We address the question of whether advertising effects vary across the hours of the week and thereby provide opportunities for the company to optimize its media plan. We summarize the data with a random-effects hierarchical linear model that treats the hours within the week as a panel of 168 interrelated time series. This model highlights the intraday and intraweek heterogeneity of advertising elasticities.