[mkarliner]

Ex Shazam tech here. The signatures that the Shazam app sends are very small, so bandwith costs should be minimal. Of course, I speaking about the technology of my day 2001+, so times may have changed

[praptak]

It seems to also send the actual sound samples though.

[duskwuff]

The audio samples are ~250 kB each. A single photo would probably be larger.