I think this is an awesome implementation of what can be a tricky concept.

Out of curiosity, what percentage of users use their Google accounts? Facebook accounts? Have you noticed any trends in terms of "serious" users (e.g. higher plans, more likely to convert to paid users) using a Flowdock account vs. their Facebook or Google?

I've always thought that Facebook/Google sign in worked well for free sites or "lightweight" sites (e.g. ones my entire business doesn't depend upon), but I'm curious how many people use them effectively with a site like this that's more "vital".