I think the problem with these sorts of "connect with people near you" apps is they do a poor job of providing you with a context within which to connect.
If you meet someone at a networking event, or at a bar, there is inherently some common ground or common expectation.
Something like Sonar is context-agnostic: I could be running late to something, hanging out with people I already know, at work, etc. It might be a nice idea in theory to think you are bringing people together, but the real question is do those people want to be brought together at that time in the way you are bringing them together?
If you meet someone at a networking event, or at a bar, there is inherently some common ground or common expectation.
Something like Sonar is context-agnostic: I could be running late to something, hanging out with people I already know, at work, etc. It might be a nice idea in theory to think you are bringing people together, but the real question is do those people want to be brought together at that time in the way you are bringing them together?