Besides getting song recs from friends, another use I can think of is when traveling. I'm heading to Armenia and Azerbaijan soon, and I wonder if it can find their music. If I hear a tune on the car radio or in a café, I could shake my phone and not only know what the tune is and who is doing it, but have a copy on my phone.
When in Romania there was a tune that kept popping up on the radio which had a good little horn riff I liked. We didn't even listen to the radio that much, and must have heard that tune about 5 times. But I have no idea what it was. With this app, I'd know (well, if the app could recognize the tune and had it in its database). There are plenty of Asian songs here, including one nice song I just got as a mistaken result for Hard River To Cross, but whether it includes Romanian and Caucusian music I have no idea. Would have been good to try in Israel and Jordan where we heard a fair amount of Egyptian music.