It starts with the human element. “What surprised us was how many times people were asking questions that didn’t need an answer,” Reid told the crowd at Fortune’s Fortune’s Brainstorm Tech conference in Aspen, Colo on Monday. People so often share things like expressions of loneliness and frustration, or a romantic longing for “Alexa” herself, that their editorial team spends a lot of time thinking about how the service can continually respond in ways that are relevant. “We work hard to build in these ‘delighters’ for the customer experience…. And we’ve taken that approach globally,” said Reid.

But these Alexa’s delights are not without risk.

Reid addressed a recent incident in which an Alexa device recorded an Oregon woman’s private conversation and shared it with a random person in her contact list. Privacy has always been top of mind, said Reid, ticking through a list of design elements: The device has a mute button; it lights up to show users it’s listening; and owners can review and delete whatever Alexa has recorded them asking or saying. Heck, people can unplug it if they want to. “We built in multiple safeguards and it still failed,” Reid said.

She understands how that incident makes consumers who are already concerned about data privacy even more nervous. According to Reid, the data Alexa collects is only used to improve the speech technology itself, to better understand the intent of the consumer. “Nothing else.”

Reid just celebrated her twentieth anniversary at the company, a milestone which comes with a gray badge. “To match the gray in my hair,” she joked. “We were just a bookstore,” she said when she first became of only 600 Amazon employees.

Even though Amazon boasts more than a half million employees now, she says the company operates more like a collection of start-ups. “We can try new things, fail fast, and take an interactive approach,” she said. “Alexa was a bold bet we thought we could make.”