The analyst said Amazon has more than 300 million consumers who could spend money on a potential travel offering. Morgan Stanley estimates online travel companies such as Booking and Expedia spend about $620 million a year each to acquire their global hotel room inventory, which is not a large investment size for Amazon. Morgan Stanley thinks that Amazon's entry into travel could change hotel-commission rates, as well as volume growth and market share - although any entry into the sector would take time. For Google, Amazon Travel might be good news in the near term, given that it would add a "deep-pocketed and competitive spender" to the travel search market, one of its big categories. But over time Amazon could pose a threat to Google's own travel business, especially as voice search and Amazon's Alexa assistant proliferate in consumers' lives. Get the full story at CNBC and Barron's