The market is sizable for e-commerce solutions dealing with payment failures, given the prevalence of subscription services. Building a dunning tool on top of an existing API like Lemon Squeezy's is technically feasible for an MVP within a few weeks. While Lemon Squeezy has its own mechanisms, specialized dunning tools could offer more advanced features, creating a competitive niche. The payment and dunning process is largely global, making localization straightforward for the core functionality.