Lots of iOS developers have made a lot of revenue by selling apps on Appstore. With the improvements in Appstore over the years, a lot of other ways have come up that one can use to maximize your revenue from App sales on the iOS Platform, check out these pointers.

Sales from In-App Purchases

In-App Purchase allows you to sell a variety of digital products
and services directly from your app, including subscriptions, extra
levels, and additional content or functionality.

Advertising revenue with iAd

Receive 60 percent of the revenue generated from iAd rich media
ads served in your apps. iAd is easy to implement and offers users an
interactive advertising experience.

Reach new customers with localized versions of your apps

Create an engaging, more relevant experience by localizing your
apps to reach millions of customers in 90 countries around the world.

Sell your app in volume to education

The Volume Purchase Program allows education institutions in the
United States to purchase your apps in volume for distribution to
students and faculty. You can also elect to offer special pricing on
your app when purchased in volume.

Earn commission with affiliate program

The App Store Affiliate Program allows you to earn commissions
from customer purchases on the App Store or iTunes Store that start from
links in your app.