I remember looking for such a thing and not finding it. Maybe it was added later? I tried an early version of Wave, briefly. If it was indeed added later, this

I remember looking for such a thing and not finding it. Maybe it was added later? I tried an early version of Wave, briefly. If it was indeed added later, this is an example of something Joel Spolsky cautioned against: don't do a huge marketing blitz for version 1.0 of your product. Aim for user count to increase in step with product maturity. Though admittedly this might be hard to avoid with a product that has strong network effects.