MercadoLibre has great prospects, but it is not necessarily a great investment.MercadoLibre (MELI 1.37%), the leading e-commerce company in Latin America, has been unstoppable lately. The stock rose more than 50% in the last 12 months alone, bringing its total return to a remarkable 274% in the previous five years.While existing investors celebrate its outstanding stock performance, potential investors may wonder if they should buy it today to participate in future growth.  MercadoLibre has been executing a ...