Отличная статья, видео и пример Томаса Штайнера о хороших push-уведомлениях в Интернете. A particularly bad practice is to pop up the permission dialog on page load, without any context at all. Several high traffic sites have been caught doing this. To subscribe people to push notifications, you use the the PushManager interface. Now to be fair, this does not allow the developer to specify the context or the to-be-expected frequency of notifications.