i know the stats of some websites(or webapps if you like to call them as such) which started years ago with user/pass and after integrating fb got a major better sign-up rate. most logged-in users now use the site via fb.
either mobile is majorly different, the tinyreview adopter group is majorly different, their product is majorly different or their analysis is flawed (as you have pointed out correctly)
either mobile is majorly different, the tinyreview adopter group is majorly different, their product is majorly different or their analysis is flawed (as you have pointed out correctly)