Non-response bias in internet-based advertising conversion studies

Purpose: The purpose of this study is to estimate the extent (mean and range) of non-response bias in online travel advertising conversion studies for 24 destinations located throughout the USA. Design/methodology/approach: The method uses two weighting procedures (i.e. post stratification and propensity score weighting) to estimate the extent of non-response bias by adjusting the estimates provided by respondents to more closely represent the total target sample. Findings: The results of this analysis clearly indicate that the use of unweighted data to estimate advertising effectiveness may lead to substantial over estimation of conversion rates, but there is limited "bias" in the estimates of median visitor expenditures. The analyses also indicate that weighting systems have substantially different impact on the estimates of conversion rates. Research limitations/implications: First, the likelihood to answer a survey varies substantially depending on the degree of the familiarity with the mode (i.e. paper, telephone versus internet). Second, the competition-related variables (i.e. the number and competitiveness of alternative nearby destinations) and various aspects of the campaign (i.e. amount of investment in a location) should be considered. Originality/value: This study of 24 different American tourism campaigns provides a useful understanding in the nature (mean and range) of impact of non-response bias in tourism advertising conversion studies. Additionally, where there is difficulty obtaining a reference survey in the advertising study, the two weighting methods used in this study are shown to be useful for assessing the errors in response data, especially in the case of propensity score weighting, where the means to develop multivariate-based weights is straightforward.