I think there is also an interesting embarassment factor - I felt that people did not like to be seen needing help on Jig. People that asked for help did get lots of it.
I also think the notification framework (posting to facebook would just get comments there, not on Jig; emailing people is annoying) is different for mobile rather than desktop use as well.
I still like the idea a lot so I hope Jelly unlocks the idea.
http://www.quora.com/Startups/Why-didnt-vark-com-or-jig-com-...