When I first got my iPad, quite a few years ago, now, I was curious about Shazam, and how much data it was sending back to its servers to identify a song. I set up a packet sniffer on my wifi network, and monitored just the amount of traffic to and from my iPad while using the Shazam app. I just tried it again; it's more difficult to discern exactly what traffic is Shazam, and what traffic is part of the exchange to bring up album info and other tie-ins, however, from the time I pressed the Shazam button to getting a response, my computer sent a total of 1176 bytes of data out. If that was pure audio data,, would only contain an audio sample of a small fraction of a second; certainly not enough to provide any clue as to the music that was playing. The video explained nicely how such a small amount of data could possibly match a record in Shazam's database. Thanks!