Earlier quoted context omitted.
One example: "Our goal is to do what Gmail did to Outlook: replace a popular desktop application with a better online version." is badly begging the question. I'd be surprised if gmail + Google calendar had more active users than Outlook.
Not really. (a) Gmail has a lot of users, even if it doesn't have more yet, and (b) I bet Gmail's growth is faster.
- what percentage of GMail users regularly schedule more than one event a week?
- what percentage of Gmail users use reminders?
- How much of their day is spent with GMail open?
- How often do they search Google contacts for phone numbers and other data?