iOS developer Future Games of London believes that a Freemium model can generate more revenue than paid apps.
The studio released its Hungry Shark series of games for free during a promotional period called "Shark Week", and reported a significant increase in profits.
"The success of the Freemium model leads us to believe that we will be moving away from paid apps completely," said managing director Ian Harper in a statement.
"By switching business model on Part 3 during Shark Week, we've traded 1000 downloads a day at $1 for 250,000 Daily Active Users that we can monetise through in-app purchases of optional upgrades."
The average in-app transaction on Hungry Shark is worth $3.26, making it one of the 50 highest grossing IPs in the App Store.
"Our revenue is also now correlated with DAU not daily downloads, which is great as DAU falls off much slower after a sales spike. We've also been able to give the whole game away for free and reach an audience 100 times larger, who we can also promote other products too."