Based on an exploration of the marketing strategies employed in senior citizens' communities of practice (CoPs), this study proposes that the concept of co-construction derived from learning theory is indispensable in Marketing 4.0, which builds on offline and online interaction between and among consumers and the providers of particular goods and services to create a sense of community. Adopting a qualitative approach, the researchers visited 15 Senior Citizens Learning Centers (SCLCs) in Taiwan, and employed semi-structured interview methods to probe selected interviewees' insights. This resulted in the identification of four key strategies for CoPs' marketing efforts, all of which work best if governed by a quality process known as legislating peripheral participation (LPP), which is grounded in co-construction. Specifically, it was found that an SCLC with a unique and high-quality LPP process can not only attract senior citizens' participation, but also transform their roles from customers to volunteers. The study also assesses whether and how well the four identified strategies can be implemented simultaneously, along with their implications for Marketing 4.0 and for the management of senior citizen-specific CoPs. On a theoretical level, this study highlights the differences between the educational concept of co-construction and the Marketing 4.0 concept of co-creation: with the former being a mutual engagement that integrates buyers and sellers into a cooperative interaction. This process, which takes into account the growth of group identity, individuals' sense of meaning, and marketing potential, is an important force in Marketing 4.0 that transforms customers into advocates.