## 1 Introduction  
In the era of the service economy, characterized by rapid collaborative product iteration, user needs have emerged as a crucial driver for product design evolution and a key determinant of new product direction [1; 2]. The exponential growth of user-generated content (UGC), which serves as a reflection of user needs, has been facilitated by the development of the Internet. This growth has been further accelerated by the proliferation of digital technology [3], leading to the generation of vast amounts of knowledge on social media platforms every second [4; 5]. Consequently, there has been a substantial increase in the personalization and diversification of user needs. As a result, both the scholarly community and industry exhibit a keen interest in investigating rapid product innovation methods that align with user needs. The achievement of this objective relies on the active involvement of users in the product design process [6]. To facilitate user participation, researchers have explored different approaches to open up the design process [7]. Interactive innovation, in particular, highlights the collaborative development of products among users, designers, and enterprises, leading to enhanced feedback effectiveness [8]. In the interactive innovation process, users contribute knowledge pertinent to product innovation within the community, serving as a vital reference for product development [9; 10]. Although numerous enterprises have adopted and successfully implemented a product development model predicated on interactive innovation [11], the advent of the mobile Internet introduces complexities in interaction, which are characterized by interactivity, self-organization, and non-linearity. Moreover, the nature of interactive knowledge becomes voluminous, dynamic, and unstructured, posing significant challenges for enterprises in the development and utilization of this innovative knowledge [12; 13]. Furthermore, the model exhibits several constraints. Rapid product turnover and swiftly changing online public sentiment cause customer demands to evolve quickly [14], creating a lag in product development that fails to meet these shifting demands, thereby widening the gap between customer expectations. This discrepancy may disrupt sales, inflate development costs, and diminish both word-of-mouth and customer loyalty. In addition, existing studies rarely focus on extreme users, which are those user groups with special needs or specific usage scenarios. They ignore the fact that the needs of this group may represent the potential needs of a wider population [15]. As a next-generation immersive Internet technology, the Metaverse is expected to address existing limitations by integrating the benefits of authentic, immersive experiences with realism and accurate reflections of reality alongside facilitating access to high-fidelity environments [16; 17]. Currently, the Metaverse has found successful applications across various industries including gaming, social media, film and television, education, finance, sports, office work, retail, tourism, and manufacturing [18; 19; 20; 21]. In its exploration and application, the Metaverse has unveiled numerous novel benefits and values. For instance, it enables a seamless interaction between virtual and real worlds [22]; supports the amalgamation of virtual avatars, digital, and real identities [23]; and offers diverse characteristics, advanced digital technology [24], and boundless opportunities in time and space [25]. These features are critically sought after in product development and design that leans on interactive innovation, offering practical solutions to existing challenges. More specifically, within the Metaverse, there is potential for generating vast UGC for product development, optimizing the application of UGC, and enabling universal user participation. Additionally, it boasts benefits such as convenience, efficiency, and visualization, which can effectively address current obstacles faced in mobile Internet-driven product development.