## 4 Findings and Discussion
### Discussion on Future Research Avenues
#### 4.6.1 Investigation on the Diversity of Boundary Factors  
The diversity of boundary factors can be explored in at least two directions. On the one hand, design papers can extend their concentration to boundary factors other than ease of use and usability as listed in Table 7. Although other factors are addressed in the design papers, such as telepresence and trust [130; 136], the coverage rate is relatively low, as illustrated in Figure 10. Therefore, more consideration of them may be necessary. On the other hand, unrevealed factors can be investigated. For instance, the phenomenon of prosumption may worth investigating, which describes an individual being both a consumer and producer of particular products [150; 151; 152]. In the context of virtual commerce, a notable example is the creation and sale of virtual products in online games and social VWs (e.g., Second Life). The factors related to this phenomenon can be studied from both consumer psychological study and technical support, such as through employing a digital model, or even a digital twin during the process of design and production of certain products to achieve commodity personalization and customization [153]. Figure 11: Research gaps and future research directions. 4.6.2. Investigation on the Diversity of Immersive Technology  
From the systematic review, we observe that the adoption of immersive technology almost exclusively emphasized visual immersion, even though immersive technology encompasses multiple sensory modalities such as visual, auditory, haptic, olfactory, and gustatory [23; 154]. While the existing literature has proven the effectiveness of visual stimuli on creating immersive experience, it is intriguing to investigate whether and how other sensory information affects a user's immersion state and impacts their consumption behavior. In addition, MR techniques such as holographic have not gained sufficient attention, yet it is worth studying whether it will trigger consumer responses similar to existing AR/VR/VW applications once it is ready for commercial use. Moreover, researchers can study the methodologies to organically integrate multiple sources of sensory information when designing the immersive virtual environment for a virtual commerce application. Finally, researchers should be aware of technology evolutions and their potential value-added toward virtual commerce, including maturing MR products and emerging immersive technology. For example, the launch of Neuralink in 2020 ([[https://neuralink.com/about/](https://neuralink.com/about/)]([https://neuralink.com/about/](https://neuralink.com/about/)), accessed on 16 November 2021) has raised awareness of brain-computer interfaces. This interface utilizes a user's neural oscillations (or brainwaves) as a type of sensory information to interact with the physical world. Considering that navigability can impact ease of use and usability according to Table 9, researchers may be curious whether brainwaves input can achieve more efficient navigation in the immersive virtual environment of a virtual commerce application. 4.6.3. An Organic Behavior-Design Research Circle  
To explore research opportunities concerning a factor, researchers can combine a rigorous behavior analysis with a design study (analyze-then-design paradigm), the former of which can theoretically justify the significance of the discussed problem, while the latter realizes a practical solution to it. Correspondingly, a behavior paper can re-evaluate a proposed behavioral theory by conducting empirical studies considering new designs (re-evaluation paradigm). For example, some previously ignored factors may become outstanding, suggesting the need for a design concentration shift for subsequent research. Furthermore, it may even identify new boundary factors, extending the knowledge base of consumer behavior in virtual commerce. Together, the re-evaluation paradigm and the analyze-then-design paradigm can constitute a research circle that efficiently pushes forward virtual commerce research and applications. 4.6.4.