Other tablets advertise that this email was sent from XYZ tablet. I would not mind advertising when an email is sent from my nook. Perhaps there could be a setting to enable a "sent from my nook" message appended to my outgoing email. What do you think email app developers?
The built-in email client already has this capability (and it is enabled by default). If you go into your settings there is a box for "signature" which is the default of "sent from my NOOK".