[Zoo3y]

As someone who scrobbles everything I listen to, I love last.fm There's a lot of other active scrobblers and music communities who use their last.fm profiles to compare their music tastes. Developers have made their own scrobbling extensions for youtube and soundcloud, as an example. Other cool projects use last.fm's API to aggregate someone's scrobbles and make cool visual charts. Every online music community I know of uses some form of this data to share what they listen to.