Notably, the bot steers clear of topics that could land it in the headlines, like you saw with Tay. Ask Zo about politics or Hitler, for example, and it will not-so-subtly try to guide you away from the subject. It's also uncannily knowledgeable about Microsoft products, and will profess to being a Windows phone fan.

Kik is an unusual proving ground for Microsoft -- you'd expect it to try the bot on Skype or a very large third-party service like WhatsApp. A mid-sized service like Kik makes sense, mind you. It limits testers to those who are genuinely interested in what Zo can do (you can request an invitation if you'd like to try), and reduces the chances that gaffes will reflect badly on Microsoft. If Zo branches out to other platforms, it'll likely happen only after the crew in Redmond is confident that its bot will behave.