The document discusses the problems solved by long tail businesses for customers, partners-suppliers, and owners-investors. For customers, it provides more access to free music in various niches and styles, as well as opportunities to share ideas about artists. For partners-suppliers, it allows them to target more customers with a diversity of music and services, and get feedback to improve quality. For owners-investors, it creates opportunities to promote new artists, develop new business features with artists, and generate new profits through various services.