It's mostly three things according to my friends who use streaming services: 1) discovery: Spotify is great at giving you more of what you like, without you ne

It's mostly three things according to my friends who use streaming services: 1) discovery: Spotify is great at giving you more of what you like, without you needing to manage your library 2) ease of access: No need to carry around a hard drive to have everything available 3) giant catalogue: to buy MP3s at that price and have a similar breadth and depth as Spotify (or rather: what you'd use of Spotify), you'd pay a lot more. If you just want some tunes and are happy with what's very popular, you could also stream for free from Youtube.