I'm sure Dr. Hammond will have a comment on that, but I would suggest that it's the missing piece. We don't know what the conversion rate is. I think some of the early evidence would suggest it's not very high. There is a lot of experimentation, but it doesn't seem like many people go on to become regular users. Maybe it's a little early to fully answer that question.
On November 4th, 2014. See this statement in context.