In fact there are more details on the Indiegogo page. Can you take a look and tell me if I have to add some details? (http://www.indiegogo.com/projects/notifon-the-notifying-obje...)
"Sensors
Notifon is universal. You can use any sensor that has two states, such as a switch, a push button, a magnetic door switch, a relay... Notifon allows you to predefine a set of actions for each state."
Just put that (or a simplified form of it - a graphical illustration is helpful) somewhere quite visible on the actual product page?