I've been thinking about this recently, and I'm not sure if the initial gold-rush of users wouldn't be just as bad. The risk there as I see it is everyone joining en-masse, kicking the tyres, and leaving again -- accompanied by a slew of articles saying "users leaving droves".

I'm honestly not sure how you do successfully gain traction in something with this much level of (unavoidable) publicity. One thought I had was that something like video chat might attract people just to use that, and then perhaps organically discover other features that make them spend more time there.