Spotify is a streaming music service with over 16 million songs. It has three tiers - free with ads, unlimited streaming, and premium with no ads. Advertisers can run audio, display, and other ad formats. To be effective, ads need to identify users' music interests, adapt to their context and mood, connect through shared passions, and encourage co-creation like branded playlists. Interrupting users negatively impacts brands, while engaging ads add value.