Until very recently, developers who wanted to add a skill to Microsoft’s digital assistant Cortana had to fill out a roughly 30-line form and paste it into an email to the Cortana team, with links to their privacy policies and terms and conditions. Then they had to wait for sometimes weeks to get feedback and final approval.

Amazon’s Alexa team, in contrast, has a portal for developers to upload details of their proposed skill. The Alexa team checks in via email if it needs more information. Approval can come within hours of a submission. The differences in the approval process for skills—the digital assistant version of apps—is likely one reason why Cortana only has a few hundred skills compared with Alexa’s 40,000.