The biggest difference between Spotify and Pandora used to be that Pandora's auto-pilot radio format attracted some listeners who wanted the experience of listening to a tailor-made radio station. Well, Spotify just launched a radio feature that creates similar stations based on your listening history.
To make matters worse for Pandora, Spotify will make the radio feature free on its iOS app in the United States, instead of charging something like Pandora's monthly $3.99 fee. Spotify's plan is to play only three minutes of advertising for every hour of listening, and users will be able to star radio tracks to have them automatically added to their Spotify library.
To compare the services, Pandora's library is estimated at 800,000 tracks, while Spotify's dwarfs that number with around 15 million songs. Now that they aren't the internet radio front runner, this very well may be the nail in Pandora's coffin. [PC via DS]