So
Amazon tried to get into the ticketing business recently, and a buddy of mine was on the dev team. Technically it wasn't hard, but the whole industry is so shady that Amazon ended up backing out. One example he gave was that frequently they would get a contract to sell X tickets. Once they sold those tickets, then the event would turn around and tell them that they could only deliver a portion of the promised tickets, so Amazon was left having to refund the rest.