Basically any situation that is some combination of in-person and online. Sure, you can build and maintain an app and then force people to install it to receive notifications. Or you can use/abuse SMS and force people to give their (highly targetable) cellphone number. But both of those alternatives cost more and are less consumer-friendly.
Basically any situation that is some combination of in-person and online. Sure, you can build and maintain an app and then force people to install it to receive notifications. Or you can use/abuse SMS and force people to give their (highly targetable) cellphone number. But both of those alternatives cost more and are less consumer-friendly.