The store facilitates discovery of your app, secure installation of your app, world wide distribution of your app, and offers customers a safe, trustworthy, consistent and easy to use purchasing system complete with refunds, subscriptions cancellation for all purchases.

One of the biggest developer benefits is Apples app reviews process. While not perfect for devs, it helps ensure customers feel safe buying my apps free of the risk of viruses, malware, and fraud ware. That sells more of my apps.

If you don’t understand these things, you don’t understand your customers.