S. Siddarth et A. Chattopadhyay, TO ZAP OR NOT TO ZAP - A STUDY OF THE DETERMINANTS OF CHANNEL SWITCHING DURING COMMERCIALS, Marketing science, 17(2), 1998, pp. 124-138
We present a conceptual framework to describe the commercial zapping p
henomenon and use it to identify factors that influence channel switch
ing during commercials. Drawing on previous research, published report
s of practitioner gut feel, interventions used by advertisers to reduc
e channel switching, and proprietary studies reported in the published
literature, we describe how these variables might potentially affect
the decision to zap a commercial. We use a latent class approach to mo
del the impact of the identified factors on two aspects of the switchi
ng decision-whether or not a commercial is zapped (modeled with a bina
ry legit model) and, conditional on a zap having taken place, the numb
er of seconds that the commercial was watched before being zapped (mod
eled within the proportional hazards framework). The model is estimate
d on telemeter data on commercial viewing in two categories (spaghetti
sauce and window cleaners) obtained from a single-source, household s
canner panel. The results from the empirical analysis show that househ
olds can be grouped into two segments. The first, which consists of ab
out 35% of households in the sample, is more zap-prone than the second
. For this ''zapping segment,'' the probability of zapping a commercia
l is lower for households who make more purchases in the product categ
ory. Also, zapping shows a J-shaped response to previous exposures to
the commercial, with the associated zapping elasticity reaching its mi
nimum value at around 14 exposures and increasing rapidly thereafter.
This finding suggests that advertisers should be cautious not to use m
edia schedules that have excessive media weight or that emphasize freq
uency over reach. We found that zapping probabilities for ads aired ar
ound the hour and half-hour marks to be significantly higher than for
other pod locations. Based on these results, we argue that prices for
advertising pods located around the hour/half-hour marks should be bet
ween 5% to 33% lower than those in the remaining portion of the progra
m. We explore the impact of advertising content on zapping and find th
at the presence of a brand differentiating message in a commercial cau
ses a statistically significant decrease in zapping probabilities. Whi
le the magnitude of this effect is small, the finding suggests that it
may be helpful to include qualitative variables in future models of a
dvertising response. We propose the expected proportion of time that a
n ad is watched as a benchmark to compare 15-second and 30-second ad f
ormats from a zapping standpoint. We found no significant differences
between the two formats on this dimension. Our analysis also shows tha
t, due to the impact of previous exposures on zapping, the use of 15-s
econd ads runs a greater risk of reaching the threshold exposure level
beyond which zapping probabilities start to increase. This implies th
at while managers must be cognizant of the risks of overexposure for a
ny ad, it is especially important in the case of the shorter, 15-secon
d ad format.