EchoNest's were the best at the time because they added social data into the mix. They analyzed people's playlists/libraries to generate recommendations when everyone else was using descriptive metadata, audio comparison, or manual curation.
Re:Ted versus The Media Lab [video]
by proximitysauce on Tuesday January 28, 2020 @03:25PM
(#22173685)
That's incorrect. Most of those services were using collaborative filtering social data to drive their recommendations.
There were a ton of music recommendations available at the time. Every music service had them: Rhapsody, Yahoo! Music Unlimited, Last.fm, Mog, iTunes, Grooveshark... Echo Nest's weren't even that good. I don't think they had song level recommendations iirc.