Subscriber is connected to the ISP's network and browsing some website.
As subscriber is browsing, ISPs can show them an in-browser messages like Bill Payment Reminders, Plan Upgrades, Upselling of VAS, etc.
To show this message we do not need any permission from the user, no browser plugin or software is needed which means the ISPs would be able to show targeted in-browser notifications in real-time to their subscribers seamlessly across all devices