Companies make all sorts of acquisitions, insightful or random. The acquisition of Echo Nest certainly isn't the reason for "the impact of Spotify on our culture". I assure you, Spotify's success was in its licensing a very large selection of music to stream. Everything else is marginal.

Not true at all. Do you think Facebook would be as big without their feed, or YouTube as big without recommended videos or their front page?

Recommendations and turning that into useful products (like auto generated playlists, mood playlists, upcoming talent, etc) are a huge draw to Spotify and creates a high bar for new competitors (including Apple Music).

> It's the music discovery engine,

Didn't the Music Genome Project / Pandora do this half a decade before Spotify?

that's a great question - those approaches where based on acoustic similarity. Later approaches, including Echo Nest, included social features.

An example I used to use with Brian was that Bad Religion and NOFX sound similar. However, fans of one of those bands weren't often fans of the other. In this model, people have a need for an amount of that sound and a social connection, NOT a need for more and more and more of that sound.

Another diff is that Pandora used human music experts where EN used machine listening. They have some overlap, and some differences, but obv the machine listening is offline.