Maybe I'm just old (28, a couple years older than these guys). But I don't get it. And I'm very much over this "growth hacking" trend. Asked for contacts, I said sure, figuring I'd see if anyone I knew actually used it. I'm now being prompted to share the app with everyone I know on every view of the screen (and it tells me how many friends they have on the service, which just feels weird to me).
At least the growth hacking will aid the inevitable "pivot", where they go Sync.me and sell all that contact book data.
I know I'm just being bitter and jealous. But the app doesn't even support the iPhone 6 screen size! It's literally a hand few of views! Like, how does the New York Times do a full expose on this? Like I wish I could offer to do the UI layout fixes for free, just so I could be less embarrassed that this is one of the top apps available today in my industry.