It sounds so simple on the face of it: just sell it yourself online. The reality is that promoting and managing any artist's career requires a skill set beyond that of many if not most artists. Theoretically it's possible to self manage effectively, the reality is that few know how at the outset of their career to develop themselves and make business decisions that are in their long term self interest. As previously mentioned, expertise is needed in tax, accounting, marketing, & legal issues.