An email recipient who got your message via forwarding from a subscriber. (Some emails offer “forward to a friend” in the creative, but the vast majority of pass-alongs happen using email clients, and not that tech.) Pass-alongs can affect the formatting of the email, often stripping off HTML. Also known as viral.

Advertise Do not Spam
There is a fine line between advertising and spam and unfortunately many business owners do not understand the difference between the two.