Amazon's US marketplace remains the top choice for sellers, with 73% of new sellers achieving their first sale within 12 months—far surpassing rates in Germany (38%), the UK (32%), and Canada (16%). The US market's unparalleled traffic volume and niche viability (e.g., "sourdough starter jar" garners 26,766 monthly searches vs. 179 in Australia) enable specialized businesses to thrive. Despite rising fees and competition, the US offers superior scalability, while international expansion often proves challenging—69% of sellers operate in only one marketplace. However, long-term success remains competitive, with under 8% of pre-2019 seller accounts still active.