Cassie's company will generate revenue by _____.

Cassie's company will generate revenue by carrying advertising on the app because this is a common and effective monetization strategy for mobile applications. By allowing businesses to advertise within her app, Cassie can earn money through various models such as pay-per-click or pay-per-impression. This approach leverages the app's user base, generating income while providing advertisers with access to potential customers.

Moreover, advertising can be beneficial for both Cassie and the advertisers, as it allows Cassie to keep the app free for users while generating revenue. The success of this model often depends on user engagement and the number of active users the app has, making it a scalable option. In contrast, selling or leasing the app to another company requires significant up-front transactions that may not provide ongoing revenue streams. This makes advertising a more sustainable option for many app developers.