The unprofitable world of robot vacuums.

They're cool and trendy, and it's not just the tech-savvy crowd that is buying them—busy parents and pet owners are also on board. Robot vacuum cleaners remain a popular household item. However, despite steady sales, profits are declining. So, why aren't these robots cleaning up in the market? / Why are seats in movie theaters red (18:50)? On the show: Heyang, Steve Hatherly & Yushun