Mastering is about as vital to the audio production process as recording!! haha. Meaning YES! Its absolutley and most definitley necessary! Without professional mastering, you mix will be left sounding dull and most likely not loud enough. Your mix simply wont have the professional touch needed to compete with the other songs on the radio. Online mastering can make the process of finding a mastering engineer and getting your tracks mastered very very easy. The process has been streamlined and the prices are much lower than traditional mastering facilities. Audio mastering cannot be overlooked or your tracks will suffer.....bring your mixes to life!!