Notifications are endless: every time you start firefox, addon "thanks you for installing" it. If you are not logged in to pushbullet, it has a notification flag, which is just telling you to log in -- this is an abuse of the concept of notifications.

There is no mode to allow pushbullet to sign off when you close the browser, so you MUST log off manually if you are on a shared computer, etc.

Sometimes pushes don't seem to get delivered.