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The global importance of online advertising calls for a detailed understanding of consumer-specific responses to online ad repetitions. A key concern for advertisers is not only whether some consumers display degrees of “wearout” but also whether they can surpass a point at which additional exposures have a negative marginal effect: “weariness.” The authors examine a large-scale advertising campaign aimed at driving viewers to a target website, which comprises more than 12,000 users across over 400 websites. These data are analyzed using a flexible discrete mixture specification that accommodates different response shapes over ad stock and timing and parcels ad viewers into response classes based on their internet usage metrics. The resulting classes display varying degrees of wearout, with one subgroup, accounting for about 24% of the sample, evincing weariness. The model also estimates differential publisher effectiveness, with the most effective publisher being nine times more effective than the one 26 places down. The authors demonstrate that the finding of weariness is robust to all the model’s main components, with one key exception: heterogeneity in users’ ad response. Analysis further suggests that an appropriate “profiling and capping” strategy can improve ad deployment by as much as 15% overall for these data.

This paper introduces the concept of brand image–country image (BICI) fit and demonstrates that it is positively associated with consumers’ brand evaluations.

A novel methodology for the determination of iron at the ppb level by spectrophotometric flow injection analysis is described. The method is based on the control of the flow dissolution of the colorimetric reagent 1,10-phenanthroline. This is achieved by means of the minimization of the area of contact between the carrier and the solid reagent, thus allowing the use of the fairly soluble organic compound without affecting the reactor lifetime. The reagent is melted inside an acrylic column (3.0 x 0.5 cm id) in such a way that a hollow space is left in the center after cooling. This new design improves some aspects of the performance of the classical solid-phase reactors as no problems related to the increase in the backpressure of the system are evidenced. Furthermore, the total reagent loading of the column is increased as no inert support is needed. A comparison between the performance of this novel methodology and that of the conventional packed reactor was performed and several advantages were observed: the use of higher flow rates, an increase in the reactor lifetime and a decrease in reagent consumption. A mathematical model to fit the concentration profiles of the dissolved reagent as a function of the residence time of the sample within the column is presented. The application of this strategy to the determination of Fe(II) improves the figures of merit in comparison to those obtained with a single-line homogeneous system: the limit of detection is 2 microg Fe L(-1) (3s) and the sensitivity is similar to that of the batch procedure. Results obtained for the determination of iron in natural waters are also presented.

We develop a hierarchical choice model to account for the choice utility heterogeneity of individual shoppers that belong to the same household. Our model allows us to measure how much variability in purchase behavior exists among individuals in a household, and to compare this to the variability that exists across households. Because of the presence of multiple shoppers from the same household, we also extend the concept of household-level state dependence to consider state dependence at the individual level. We apply our model to five different grocery categories. We find that the intrahousehold heterogeneity in estimated brand intercepts and (to a lesser extent) price sensitivities is about 20%–30% of the interhousehold heterogeneity in these parameters. However, with promotion sensitivities, we find intrahousehold heterogeneity, in most cases, to be as large as interhousehold heterogeneity. Our state dependence results show that past brands purchased by an individual have a much stronger influence on subsequent purchases than those purchased by anyone in the household. We use our estimated utility parameters to compare the expected profitability of promotions targeted at the individual rather than at the household and find substantial (more than 50%) improvements in the incremental revenue of supermarket promotions. Data and the online appendix are available at https://doi.org/10.1287/mksc.2018.1088 .