More than a year later, Taylor Swift’s music is still nowhere to be seen on Spotify. But the streaming service experienced its biggest growth year ever in 2015, adding 29 million active users. There’s no specific star or revolutionary business plan behind this success: In large part, its growth is thanks to the Echo Nest, a music data start-up that Spotify acquired just months before Swift’s exodus. Echo Nest alums have conceived and shepherded virtually every major product update Spotify has rolled out over the last year, from Discover Weekly to its Running mixes. These features, centered on personalization, are part of Spotify’s big bet that crafting killer, user-friendly playlists will keep its followers loyal.
But in the age of streaming album exclusives, loyalty can be tough to come by. As more streaming services have entered the market — most notably, Apple Music and Tidal — major artists have started brokering deals to keep their work on certain platforms and off others.