Introduction
For several decades, marketing researchers became accustomed to working with consumer purchase data in fast moving consumer goods (FMCGs), developing approaches to guide their analyses (Graham et al., 2017). When documenting brand loyalty relative to size, use double jeopardy (DJ) (Ehrenberg et al., 1990). When outlining brands sharing customers, use duplication of purchase (DoP) (Goodhardt, 1966). These useful patterns measure loyalty toward, and competition between FMCG brands, product variants (Singh et al., 2008), and prices (Dawes et al., 2017). The recent expansion of these analytical tools includes the context of private label brands (Dawes & Nenycz-Thiel, 2013), an unusual...