Table 1.

Definitions of constructs and theoretical roots.

Category	Construct	Definition	TAM	UTAUT/UTAUT2	TPB	Other
Determinants	Ease-of-use	“The degree to which a person believes that using a particular system would be free of effort” (Davis et al., 1989, p. 320)	✓	✓Effort expectancy		✓Complexity
	Perceived risk	Risk is a probability, while uncertainty exists when knowledge of a precise probability is lacking (Knight, 1948).				✓
	Trust	Willingness to rely on exchange partners and that their ability to perform its stated function (Chaudhuri and Holbrook, 2001)				✓
	Price value	The level of price, and entails pricing-related cues (e.g., unit pricing) (Zielke, 2011)		✓
	Positive emotions	Positive emotions refer to consumers’ state of mind resulting from a cognitive and affective evaluation of their consumption (Bagozzi et al., 1999)		✓Hedonic motivation		✓Enjoyment✓Entertainment
	Social influence	A “person's perception that most people who are important to him think he should or should not perform the behavior in question” (Fishbein and Ajzen, 1975, p. 302)		✓Social influence	✓Subjective norm
Mediators	Perceived usefulness	“The degree to which a person believes that using a particular system would enhance his or her job performance” (Davis, et al., 1989, p. 320)	✓	✓Performance expectancy		✓Relative advantage
	Attitude	Consumers positive or negative feelings about putting the targeted behavior into practice (Venkatesh et al., 2003)	✓		✓
Outcomes	Behavioral intention	A consumer’s intention to perform a specific behavior (Davis et al., 1989)	✓	✓	✓