“…To incorporate interdependence between the different model components, we allow for correlations between the intercepts. 7 The expected values of the retention and usage intercepts α0i, 0i, and 0i are functions of the concomitant customer characteristics age, household size, income (e.g., Rust and Verhoef 2005), and time-to-adoption (Prins, Verhoef, and Franses 2009;Schweidel, Fader, and Bradlow 2008): where Agei, is the age of customer i (in years, shortly after service launch), Hhsizei, is the size of customer i's household (in number of persons), Incomei is the average income in the census block to which customer i belongs (in €10,000), and Adopttimei is the time-to-adoption of customer i (measured in months following the launch of the iTV service).…”