Bloomberg Businessweek: Each holiday season since 2015, Amazon.com has counted on selling a lot of its Alexa voice-controlled smart speakers. For almost as long, it’s known that the devices have had trouble holding customers’ attention even into January. According to internal data, there have been years when 15% to 25% of new Alexa users were no longer active in their second week with the device. Concern about user retention and engagement comes up repeatedly in internal planning documents that Bloomberg Businessweek viewed. The documents, which covered 2018 to 2021, detail Amazon’s continued ambitions for Alexa, including plans to add more cameras and sensors that would allow devices to recognize different voices or determine which rooms users are in during each interaction. They also reveal the roadblocks the company sees to realizing these goals. Last year, Amazon’s internal analysis of the smart speaker market determined it had “passed its growth phase”