Spotify – See which artists you were listening to before they got big (spotify-foundthemfirst.com)

I like this - got some interesting results, and I like how it tells you which percentage you're in. Apparently I was in the first 1% for Run The Jewels, Bastille and Clean Bandit, which is interesting given I'm not necessarily a fan of all those bands (I love RTJ).

The UI is very pretty but a little slow, and I'm on a relatively powerful machine!