He's referring to whether usage is going mainstream, shifting from early adopters to the general market[1]. He's looking at technology that's already big but has the potential to get even bigger.
When usage is limited only to early adopters, it's not useful to Microsoft since it's such a large company. But when general folks are also beginning to adopt a piece of technology, it's a sign that things are going right.
He's referring to whether usage is going mainstream, shifting from early adopters to the general market[1]. He's looking at technology that's already big but has the potential to get even bigger.
When usage is limited only to early adopters, it's not useful to Microsoft since it's such a large company. But when general folks are also beginning to adopt a piece of technology, it's a sign that things are going right.
[1] https://en.wikipedia.org/wiki/Diffusion_of_innovations