“…So, as experiments end naturally, business-as-usual settles in and managers continue to face the need to understand how ad effectiveness varies over time for a host of factors beyond those tested or potentially tested under experimental conditions, such as copy and restoration wear-out (Naik, Mantrala, and Sawyer 1998), product life cycle stage (Kolsarici and Vakratsas 2015; Osinga, Leeflang, and Wieringa 2010), ad content (Kolsarici and Vakratsas 2010), competitive interference (Danaher, Bonfrer, and Dhar 2008), or product harm crisis (Rubel, Naik, and Srinivasan 2011; Van Heerde, Helsen, and Dekimpe 2007). In addition, temporal variation may be due to seasonality and coordination with promotional campaigns.…”