With the ability to purchase more content or features within an application, in-app purchases have grown to be a substantial source of income for mobile app developers. App monetization success depends on an understanding oslots megawaysf the psychological aspects driving these purchases. A common tactic is the "freemium" model, in which users can download and use the app for free & opt to pay for additional features. This strategy makes use of the idea of providing basic services without charge in order to entice users to pay for more expensive features. To make sure users feel their purchases are worthwhile, developers need to find a balance between free and paid content.