Customer Service is a necessary but time-consuming process for those who sell their own products. As an Affiliate, you aren't the product owner, and therefore aren't responsible for keeping the customers satisfied. Occasionally you may get Customer Service questions or requests from people who aren't aware that you are just an Affiliate. In this case, you simply refer them to the product owner.
The music industry might not be as strong as it was in the 80s, but there are still plenty of ways to make money online as a musician. Sites like SoundBetter let you sell your services as a songwriter, producer, or session musician to thousands of customers a month. While Musicbed, Music Vine, Marmoset, and SongFreedom are perfect for licensing your music to TV shows, movies, and web series.
However, as you might already likely know, this does require a tremendous amount of effort. Not only do you need to have the products, services and information that you intend to sell, but you also need to build an online shop then get people to visit it. You need some serious knowledge of online marketing and search engine optimization in order to do this. It’s not easy by any means.