Amazon.com's (NASDAQ:AMZN) Echo line, powered by its AI personal assistant, Alexa, holds 70% of the smart speaker market right now and could add $10 billion the company's top line by 2020. Additionally, Alphabet (NASDAQ:GOOG) (NASDAQ:GOOGL) is using its own AI, called Google Assistant, to power its own competing line, and the smart speaker rivalry is only going to grow.