The Music Genome Project conceived by Pandora is the foundation for one of the most successful streaming radio apps of all time. But any serious audiophile who spends more than few days on the service quickly begins to notice the same tracks and artists repeating.
Part of the reason the catalog feels shallow is because its expensive to license new tracks. But another reason is that the Music Genome relies on human experts to evaluate each track, an extremely time consuming process. It’s why Pandora has less than 1,000,000 songs while competitors like Rhapsody have ten times that.