Background and motivation. Online platforms frequently deploy nudges—short prompts or design elements intended to influence user behavior—in a wide range of contexts, from increasing engagement with digital products to encouraging healthier choices. Despite their widespread use, key challenges remain in optimizing nudges over time, particularly when users' responsiveness is unknown and repeated exposure to the same nudge leads to diminishing returns. This work introduces a novel framework to address these challenges, focusing on the interplay between unknown user responses, the cost of generating or refreshing nudges, and fatigue effects from repeated exposure to the same prompt.

We study resale platforms, an emerging type of online marketplaces in developing countries. Resale platforms are designed for individuals (resellers) to sell products to others as opposed to buying for themselves, enabling them to supplement their income by earning a margin on the transactions they generate. One challenge these platforms face is that competition among resellers may emerge as more of them join the platform, as their social circles increasingly overlap.

Artisanal supply chains play a significant role in the economy and social sustainability of many developing countries. The total value of the global artisanal and handicrafts market was $526 Billion (USD) in 2017 and is expected to reach $984 Billion (USD) by 2023 [NEST, 2018]. The sector is also the second biggest source of employment for rural women, especially for those from the under-privileged class. Unfortunately, while the artisan sector plays a crucial role, many workers in this sector struggle with low productivity and poverty, in part due to the highly distributed nature of the supply chain [Banik, 2017]. A significant fraction of artisanal production in developing countries is still conducted by artisans from their individual households that are dispersed across large geographical areas, thus posing numerous challenges including low productivity, limited access to financing, technology and quality control in the upstream of such supply chains.