Simply put, mastering is like icing on a cake. Who like’s cake without icing? Sure you can eat the cake by itself without the icing. They go hand and hand if you ask me. That’s how I look at mix and mastering. They both are important and needed when it comes to how good it’s going to sound overall. You don’t NEED mastering, but keep in mind that the greats get their songs properly mixed and mastered before they are heard by the world. If you want to make a good impression on people with your music you should highly consider mastering your tracks after they are mixed.
It’s obvious that most artist underestimate the importance of good sound quality and how it effects the listeners perception about them or their music. We only have one time at a first impression and we want to make it a good one. So before you release any of your tracks, make sure they are at least mastered properly so it’s pleasing to the listeners ears. I offer mixing and mastering services, if you need work done contact me or make your purchase here and ill get back to immediately.
Here’s a video I came across explaining the importance of mastering more thoroughly.