[andymism]

Agreed. On top of that, the discussion about time in app is an implicit straw man. It's no surprise that one set of metrics might be more important to LinkedIn versus for Facebook, but the relative importance of a set of metrics for two different businesses targeting different audiences is a weak argument for their relative valuations.

Facebook has fundamentally changed the way millions interact with their social circle; LinkedIn's impact is smaller by far. I find this a pretty simple explanation for much of the difference in their valuations.