Argentina, Brazil, and Mexico are seeing explosive growth in online sales, serving as a strong tailwind for MercadoLibre (NASDAQ: MELI) -- the leading online-commerce ecosystem in Latin America. The stock fell hard over the past year, as sales of TVs dropped amid supply chain issues and inflation pressuring consumer spending. While Wall Street worries about the near-term advertising market and TV sales, the stock is trading at its cheapest price-to-sales valuation since going public five years ago.