With Kobalt's release of a streaming data app come fresh dates for some of its AWAL indie music services clients. Collectively they show that, even for virtually unknown clients, inclusion in official Spotify playlists leads to both a spike in streams and a significant amount of lasting interest.
Below is data for two artists, Guordan Banks and Michael Brun.
Kobalt tell TechCrunch that they generally see a boost of 50-100% after artists are added to official Spotify playlists. Even after the spikes wear off, the artists usually see a 20% increase in streams.