We’ve read at mashable a number of interesting tips for developers to monetize their apps through In-App Purchases. That article is very comprehensive and highly recommended. What we have learned there can be summarized in one big point.
There are plenty of users that have never posed to pay for an application. Given the proper encouragement and showing them how much worthy is we will gain a customer. That is where developers must aim.
One good example is Gun Bros:
Notice that Android market is still young and there is room for innovative strategies. One of the most successful is developing a free app that engages its users but needs a payment to unlock certain features. Be creative and imagine new ways to play with this interesting choice. The actual price of the application is not always the most discouraging to users, but the hassle of giving your data to execute the payment instead. A customer who has good results with his first purchase will be inclined to make a second. Assure the customer a first good experience and he will come back looking for more and more expensive upgrades.