Sorry for the negativity, but I can't see how this would work. It suffers from the same problem as every social network does, people need to be on it. If I want to get responses from my friends instead of just googling it, I go to my biggest social network Facebook to get those. I just don't see any value in this, it doesn't solve a problem any better than the current alternatives do.
My understanding was that it works as an addon to facebook or twitter or whatever. Maybe one of the creators is floating around here and can clear this up.
EDIT: The app uses friends of friends on Facebook, and also the Twitter Followings of your Facebook Friends.
The big down side is this: "“What’s this?” That query is submitted to some people in your network who also have Jelly".
I have +400 friends on Facebook. Out of those, maybe 3 will install Jelly to try it out. Even with taking friends-of-friends taken in to consideration, it's just a very limited set of people. Would I really want to use this app to post a question that I can probably find answer just by looking a map, doing a google search or posting to Facebook/Twitter?
What a silly world these people live in.